Ct-f Ef\;'\ I S T~ Y GLASS XJI - ·

HALOALKANES I HALOARENES

1- Important terms and concept

R-H +X2--+R-X + H-X

(i) Halogen derivative of alkenes called halo alkenes e.g. R- CH3

(ii)Halogen derivative of arenes called halo arenes e.g. R- CI-Is

2. (a) Vicinal di halides -where the two halogens are attached on the adjacent carbon atom.

e.g.CH20

I CH2Cl

(b) gemmal dihalide- where two.halogen atoms are attached to the same carbon atom eg

CH3CHBr2

2- Important mechanism (i) Nucleophilic substitution (ii) Electrophilic substitution

(iii) Elimination reaction

(iv) Carbylamine reaction (v) Reimer Tiemann reaction

(vi) Wurtz reaction (vii) Wurtz fittig reaction

Nucleophillic substitution atom or group

it involves the replacement of an atom or group by another

,

A-B+c-+ A-C+B

It must be remembered that A - B and A - C both are covalent compounds. (i) In aliphatic system

R - X + OH· --+ R - OH + X·

R-X+ OCVis -+ R-0-CiHs+ X-Decreasing order of Basidty CH3 > NH2 > OR > OH·> I·> Br> Cl ·

In general R - X + :B- -+ R - B + X·

179

II

: B--+ OH-, RO-, CN-, RCOO-, N03·, SH-, RS·

Bimolecular Nuclephilic substitution SN2

H3C

(i) 1t takes place in one step.

( ii) Most of the SN2 reaction are second order but some time when N ucleophillic

reagent is present in excess quantity the react ion is of Its order but still proceeds by SN2

(iii) It is bimolecular

(iv) It leads to inversion of configuration attack of Nucleophillic occur from direction opposite to the leaving group.

J "'-c- s, HO· / ~~Hs (inversion)

Hea t

CI-la

HO --e6.i + Br·

\

S:\": .......,. (i) It takes place in two s teps.

(ii) All aie Jstorder. (iii) Unimolecular

(iv)It leads racemisation Retenation (v) Retention of configuration (vi)

~~ ~~

H~c" __ Br ____ H ~-OH CHi / CHJ /

+ Br-

The preservation of spa tial arrangement of bonds at an asymmetric centre during the chemical reacti on.

Stereochemistry of S'NI reaction

It an alkyl ha lide is optically active then the product is racemic mixture, here the attack of !\'ucleophi lcs from the both side [50:50 mix of the two enantiomers.

180

+ B(

CH~ /3 H c OH HO c H

50% c{Hs C2hs 50%

~ Mg x

20 RH+ Mg (OH) X

RH+ Mg (OR')X

R COOH + Mg (OH) X

R .Mg- X H CRO RCH:OH

H+/ H,O

R- CHO ~ ~CH-OH

HCN -. R C=N Mg>CR • RCHO .•

. ·. H20/H• . *- CN R2 t<=N IVlgA _,

.,. 181

R- X -

HOH or Reaction is known as hydrolysis

. R OH, NaOH/HOH •

R' 0-No R-O -- R', Ethers

Na·s·H R- 5 - H Thio Alcohols

NaiS R-.

R'S.Na' ., R_S

" S -R Thio ethers ·

_ R' Thio ethers

::: R-~ -R Sulphonium Ions

R NaCN .. R- Ci1 N Alkyl cyanides

Na""N2· .. R- N3 Azides

R'-C!ZCNa• R'-- cm C -R Non terminal akyne

0 0

C-~-0- R'-C-1~~ Ester . •• R'3N~

R-N-R13X• Quaternary ammonium halide H.

R- H Hydrocarbons From UAIH.

a· - N =O R -0-N = O + R Alkyl nitrites

From Na•o·-N=O 0

AgN03 ..

-Ag-C111N .. R'Mgx

R'Li .

R'2Culi .

~.,' R - o - N = o +R - Nr 1

(Minor) (major) ~O Nitro alkanes

R- R'

R- R'

R- R' 182

lsocyanides

Hydrocarbons

Hydrocarbons

Hydrocarbons

R-OH •

Dry Ag20 _ __;;;_.;..i_~-liiM-~----., R- 0 - R

Electrophilllc substitution sees in aromatic compound mech.

H y H y H y

H y +

OR

H y y

fast (JJ +HX

E.g.'Nitration - how Electrophiles produce.

OR . . .

• I

. '

18~

y+

N+02

+ [Cl-Cl +FeCh -+ CI++ CI- FeCb]

503 [ 2H2S04 S03+HJO++HSQ4·

Sometime

· ~+H2S04

"""' HS04 - + HS03+

+ [GhCl+AlCb ~ CJ-ht- CI- -AlCb ]

CH3CO+ [ CHJCOCI+Al03----+ CHaCO+-AICk J

Elimination reaction

Two groups or atoms attached to two adjacent carbon atom and simultaneous formation of multiple bonds bct-.-\·een lltt'se carbon atom.[Reverse of addition]

Two types (i} bl Elimination - [ E1 --. Two s tep eliminate

E2 --. One step eliminate (ii) a- elimination

)

1c_h<--)C=c( +H X

H

Saytzaff's Rule

(i)

Aloe.KOH

Cl-IJ- CI-h- er- CI-b ---.

Br

ca, - CH = CH - O:b

[

81 % More highly subs tituted Alkenes]

More stable

184

Some important name reaction

1. Carbylamines reaction. R- NH2 +CH Ch +3 KOH ---R.NC + 3KCI +3H20

2. Reimer Tiemann Reaction x

OH . 6 CHCI, + aq NaOll

lntcnncdiatc

3. Halofonn reaction CH3CH20H ~ 4h+ 6 Na OH ~ CHh +HCOONa+ 5Nal +5H20

CH3CHOH CH.3+4h+ 6 Na OH~ ·CHh +ClliCOONa + 5Nal + SH20

CH3COC,lli + 3h + 4NaOH-. CHh + C;HsCOONa +3Nal +3H20

4. Wurtz reaction

R-X + 2Na +xr ether R-R+2 NaX

WurtzFITIIG REACTION

C;HsBr + 2Na +Br+ C:?Hs ether .,0.Hs C2Hs+ 2 NaBr

Coupling reac.

CJisN2.+Cl· + H--(Q)- Ol=I=-~• @)- N@

-Nlh .Q - NG -NH

"

185

01 1

h11 11l

l_:/ SaJicybldt.:hycic

Diazonium Salt

H3POi C6H 6

Alcohol CJ-It,

CuCl / HCl • C H; Cl J CoHsN2·X· CoHs Br Sandmeyer reac

CuCN ~HsCN

C6HsN02

CoHsOOC CI-h

CONCEPTUAL QUESTIONS

Ql. Why haloaJkanes are more reactive than haloarenes.

Ans. Jn ha loarenes, there is double bond character b/ w carbon and halogen du e to

r\.·sonance effect which makes him less reactive.

(ii) ln benzene, carbon being sp2 hybridised which is smaller in size than sp3 present in

haloa lkanes. So C-CI bond in aryl halides is shorter and stronger.

Q2. Why do haloalkenes under go nucleophillic substitution whereas haloarenes electophillic substitution.

/\ns. Due to more electro negative nature of halide atom in haloalkanes carbon atom ·oecr.-..:111

slightly positive and is easily attacked by nucleophillic reagents.

While in haloarenes due to resonance, carbon atom becomes slightly n-=~:::: ·. :­

attacked by electrophillic reagents.

186

Q3. When an alkyl halide is treated with ethanolic solution of KCN, the major product is alkyl cyanide where as if alkyl halide is treated with AgCN,the major product is alkyl isocyanide. •

Ans. KCN is ionic they can attach through C or N but C-C bond is strong than C-N bond. So alkyl cyanide is the major product but AgCN is covalent so more electronegative N can attach

to C and forms isocyanides.

Q4. How do 10 20 30 alcohols differ in terms of dehydrogenation ?

Ans. 1°alcohol Cu,300°c aldehyde

Cu.300°c 20alcohol ketone

. Cu,300°C 30alcoho1 alkene

QS. Why a.re the reaction of alcohol /phenol with add chlorjde in the presence of pyridine?

Ans. Because esterification reaction is reversible and presence of base (pyridine ) nuetralises

HCI produced during reaction thus promoting forward reaction .

Q6. Explain why o-nitrophenol is more acidic than o-methoxy phenol?

Ans. -N02 group is electron with - drawing group, e- density on 0 decreases and loss l)f H"' is

easy whereas -OCH3 group is electron releasing group , which increases e· densitv on 0 , v•hich

makes difficult to the loss of H+, hence e1re less acid ic .

Q7. Aryl halides cannot be prepared by the action of sodium halide in the presence H2SOl .Why?

Ans. Due to resonance the carbon- oxygen bond in phenols has partial double bond and it i:-;

stronger than carbon oxygen single bond.

QS. Why Grignard reagent should be prepared under an hydrous conditions.?

Ans. Grignard reagent react with H20 to form alkanes, therefore they are prepared under anlwdrous condition.

187

Q9. Why is Sulphuric acid not used during the reaction of alcohols. with KI?

Ans. It is because HI formed will get oxidized to h by conceritrated Sulphuric acid which is

oxidizing agent.

Q l O. p- dichlorob enzene has highest m.p. than those of ortho and m-isomers.?

1\ns. p- d ichlorobenzene is symmetrical, fits into crystal lattice more readily and has higher

melting point.

Qll. Although chlorine is an electron- withdrawing group, yet it is o rtho and para dire · in electroph illic aromatic substitution reactions .Why

Ans. Chloroben zene is resonance hybrid, there is - ve charge at 0 and para positions,

f'.lectrophillic substitution reaction w ill take place at 0 and para position due to +R effect. +R ~ffec t is d ominating over - r effect . .

•• •• (·~Cl· ·O · • .,-· ·- ·Cl::..j ·CI·· ~ · . . ·'-.. . h ..

c;(b --Q-0 -0 -0 Q12. The treatment of alkyl chlorides with aqueous KOH lead to the formation of alcohols

b ut in p resence of akoholic KOH alkenes are major products. Explain?

Ans. In aqueous KOH,OH· is nud eophile which replaces an other n ucleophile.

R-X +KOH R-OH +KX

Where as in alcoholic KOH

CH 1CH 2-Cl + alcoholic KOH

Q13. Explain w hy vinyl chloride is unreactive in nucleophillic substitution reaction?

Ans. Vinyl chloride is unreactive in nucleophillic substitution reaction because of double

bond character be tween C=CL bond which is difficult to break.

fl 16_0 CH 2 = CH- Cl -. CH2· -CH =CJ+

00 188

Q14. Anange the following compounds according to reactivity towards nucleophillic substitution reaction with reagents mentioned:-. ) '

(i) 4- nitro chloro benzene, 2,4 di nitro chloro bemzene, 2,4,6, trinitrochlorobenzene

with CH3QNa

Ans- 2,4,6, trinitrochlorobenzene > 2,4 dinitrochlorobemzcne > 4- nitrochlorobenzene

Q15. Which compound will react faster in SN2 reaction with OH- ?

Ans- (a) CH3Br and Cl-LI

CH3l will react faster than CH3Br

(b) (Cli3)3C-Cl or CJ-hCl

Cli30 will react fas ter than 3° halide

Q16. Arrange in order of boiling points.

' (a) Bromobenzene, Bromofo:n;i, chloromethane,Dibromo-methane (b) 1-chloropropane, Isopropyle chloride, 1-Chlorobutane.

Ans. (a) chloromethane < Bromobenzene < Oibromo-methane <, Bromoform ~'

(b) , Isopropyle chloride <1-chloropropane <1-Chlorobutane

(As Branching increases, boiling point decreases)

Q 17. Predict the reactivity in SN1

, Ans. 30> 20> 10 (SN1)

C6HsC(Oi3)(~Hs)Br > ~Hs(~)Br > G.HsCH(CH3)Br > 4Hso-I2Br

(30) (10)

189

J •

Q18. Which compound undergoes SN1 reaction first?

(a) Cl and

~ Cl

Cl react faster than Cl

VERY SHORT ANS\.VER TYPE QUESTION

{11\I ARKSJ

Q:I. \\' ritt' the form ulJ. & che mical name of DDT?

Q.2 \n .:l !lyl halide ha\ ·ing molecular formula ~H9Cl is optically active. what is its structure?

Q.3. \\"hy is vinyl chloride less reactive than ethyl chloride?

Q.-1. Write the structural isomers of C3H 6Ch which can exihibit enantiomerism ?

Q.5. Write down the structure of the following compounds;

(e1) 1- chloro-4-ethyl cyclohexane

(b) l,4-dibrone but-2-ene

(c) 4-tert,butyl-3-iOi.:oheptane

(d )1-bromo-4-secbutyl-2-methylbenzene

Q .6. Which compound (Cfu)3- C-0 or ; CH3Cl will react faster in sn2 reactionwith -OH?

Q.7. A hydrocarbon CsH10 does not react with chlorine in d ark but it gives a single monobromo

compound in bright sunlight.identiiy the compound.

Q.8. \i\'hy is sulphuric acid not used during the reaction of alcohols with KI?

190

Q.9. Out of C6HsCH2Cl & C6HsCH2Cl 6Hs which is more easily hydrolysed with aq. KOH &

why?

Q.10. Chloroform is stored in dark coloured & sealed bottle. why?

Short answer type questions

Ql. Give the IUPAC names of the following compounds?

A)OCH2C = CCH2Br

C)CH3CH (Cl)CH(Br)CH3

b) (CCb)3CO

Q.2. Starting from methyl iodine, how will you prepare :

A) nitromethane B}methyl nitrite

Q.3. How can iodoform be prepared from ethanol ?

Q.4.predict the product of the following. reactions;

Q.S.\·Vrite the reaction involved in:

A) the isocyanide test

B) iodoform test

Q.6. Rearranging the following in order of increasing case of dehydro haJogenations

GbCH2o-I2Cl I CH3CHOCH 3. CH~ - C- CHCH ::)=

Q.7.how will you distinguish between

(i) CH1NH2 and (CH:-):!NH

(ii) eth¥1ol & 1-propanol

Q.8. Give the uses of (a) CCl4 (b) iodoform

Q.9. Propose the mechanism of the following reaction :

.10. Which will have a higher boiling point 1-chloro~ntane or 2-chloro-2-methylbutane?

Q.11.How will you bring the following conversion?

191 .

(b) Toluene to Berizyle Alcohol

(c) Aniline to Phenylisocyanide

Q.12.What happen when;

(a) n-butyl chloride is treated with ale.KOH.

(b) ethyl chloride is treated with aq.KOH.

(c) methyl chloride is treated with KCN.

Q.13Cornplete the following reaction;

(a) ChCH-CH-Ch+Zn 6 .,

(c) C,H~O!\:d+C:!HsCI

3 YfARKS QUEST IONS

Q'J . How can we produce n itro benzene from phenol?

Ans. (f) First convert phenol to benzene by heating ,,..·ith Zn dust.

(I£) Nitration of benzene with cone. nitric acid in presence of cone. sulphuric acid.

Q 2. Alcoh ols reacts with halogen acids to form haloalkenes but phenol does not form halo benzene. Explain

. Ans . The C-0 bond in phenol acquires par tial double bond character due to resonance and

lwncc be cleared by X- ions to form haloben zenes. Su t in alcohols-a pure C - 0 bond is

ma int;;1ined and can be cleared by X- ions.

, Q 3. Explain w hy o-nitrophenol is more acidk thaq o-methoxy-phenol?

Ans. Due to - Rand - I effect of - NOi group, e- density on _0' if 0 - H bond decreases and loss of H+ is easy.- I effect In contrast, in o-rnethoxy phenol due to+ R effect, - OClh

increases. e- d~nsity on 0 2 0 £ 0 - H group, and hence loss of H +. is d ifficµJ t.(both -ve charge rept•I et\ch other)

192

Q4. Of benzene and phenol, which is more easily nitrated and why? Ans. Nitration is an electrophilic substitution. The -OH group in phenol increases the

electron density at ortho and para position as follows Since phenol has higher electron density due to electron releasing nature of -OH group , compared to benzene , therefore nitration is easy in phenol than benzene.

QS. How will you account for the following? Ethers possess a net dipole moment even if they are symmetrical in structure? A. Because of greater electronegativity of o- atom than carbon C - ·O bonds are polar. C- O bond are inclined to each other at an angle of 110° (or more), two dipoles do not cancel

out each other.

Q 6. How do 1° / 2° and 3° alcohols differ in terms of their oxidation reaction and dehydrogenation ?

Ans. (I) Oxidation .reactiqn : (0) (0)

1° alcohol - aldehyde - carboxylic acid (0 ) (0 )

2° alcohol-+~ ketone - carboxylic acid (acid with loss of 1 carbon atom) (0)

3° alcohol- resistant to oxidation

(II) Hydrogenation reaction: give

1° alcohol - aldehyde

2° alcohol - ketone

3° alcohol -+ alkene 3° alcohols prefer to undergo dehydration and form alken

Q7. (i)How is diethyl ether prepared from ethyl alcohol? Ans. Ethyl alcohol is first· treated with sodium to form sodium ethoxide

C2HsQH +Na Cili50- Na:+- +Hi

Sodium ethoxide is then treated with ethyl halide to form di ethyl·ether. SN2

GH50 Na + ~ GHsX -+ C2Hs0 CiHs + NaX (Williamson:synthesilr)1.

(II) Compl~ the reaction~

(a) CH30CHJ '+ PCls?

(b) C2Hs0Clb +HO?

(c) (C:!Hs)2 0 +HO

A. (a) 2 CfuO (b) CHJO + C2lliOH (c) CilisO + C2HsOH

193

QB. Why are reactions of alcohol/phenol and with acid chloride in the presence of pyridine? ·.

A ns. Becausr esterification reaction is reversible and presence of base (pyridine) neutralises

HCl produced during reaction thus promoting forward reaction.

LONG ANSWER TYPE QUESTIONS

Q!LHow the following conversions can be carried out?

(i) Propene to propan-1-ol

(ii) 1-Bromopropane to 2-bromopropane

(iii) Toluene to benzyl alcohol

(iv) Ben?..cne to 4-bromonitrobenzene

1

2

3

f ..

(v) Benzyl alcohol to 2-phen~·lethanoic acid

CH3 - CH= C'H:!

Pro~c

HRr ' Peroxide

(Am - Markovniko....­addition

CH:; - CHi- CHi - Br 1 - Bromoprop;an~

(Nuclcop1'i.lic I Aq .. .KOH / 6 substlluhon) t CU3 ·- CH2 - C'H2 - OH

Propan - I - ol

CH; .. · Cf I. ··· · Cfh ····· Or KOH (ale) I ~ I - Bro~nopro~'tl CH3 -CH = CH2 ,

{Dehydrohafop1ation) 1ropene M1rtovnil<ov · RBr addition

Br , ,, I

CH3-CH - CH3 2 - bromopropane

0 Cl~ l UV light OCI Aq. KOii 16. OOH

or heal (nuclcophilic

To lueo.: Ben:eyl substitutK>n) BenzyJ chloride alcohol

194

-

-

Br

~

l) 6 B~nzene

I IN~ / l l:S04

(Nilration)

lir

¢ NO::

4 .£ - D1omo11itrob~.nzer.e

CJl~Olt

6- J"Cl,'I

II ,,,9 - POCIJ. - HCl

Sen.iyl

1lc.ohol flcri1yl cyaric~

{~crcly~sl ! H' IH,(,

; I

5

OCOOH 2 - Phen~•letl1:ir.oir. :icid

Q2) How the foliowing conversions can be carried out?

(i) Ethanol to propanenitrile

(ii) Aniline to chlorobenze.ne

(iii) 2-Chlorobutane to 3, 4-dimethylhexane

(iv) 2-Methyl-1-propene to 2-chloro-2-methylpropane

(v) Ethyl chloride to propanoic acid

6 "Ethanol

195

l»ropancmtrtle

7

9

NH· o· 6 NaN02 I 21 IC!, !71 - 2715.

- NICI, - 2H10 .\niliat:

~llCA(di.,NWll

chloride

CH, I . . HCI CH:; -C-CHi

()obdu'llikvv 1 - Mt:'J1yl - ~ - ~"!'~•~

addition)

KC'N, a.q, ~hWlol CB~ - \Hz - Cl

(nucloophilic Etnylclllonde

subsriturion)

Cl

t12L.:b c -+ N2

Ch~JO'I<

CJ.I I ) Clf) - C - CH3

I Cl

?~hlM.'1-?..n"lt'!thylrut~111~

+

Propaneninile

I Hydroly~•l l H"' I H20

CH_, - CH~ - COOH

10 Propanoic acid

Q3) How the following conversions can be carried out?

(i) But-1-ene to n-butyliodide

(ii)2-Chloropropane to 1-propanol

(iii) fsopropyl alcohol to iodoform

(iv) ChJorobenzene to p-nitrophenol

(v) 2-13romopropane to 1-bromopropane

•

KCI

CU~ · - CH2 --· CH = Cil1 HB: I J•eroX"ide CHJ - CH:t.-CH2

- CH2

-- Br Bu1 - I - ene (l\Ati - tvwko...Okov 1 - Brom.btiMc

<idditio:i)

11

196

finkd~tn l Nal, ~I acetMd n:ctl('R

CH1 - C'H1 - CH2 - CH2 - 1

" - Bt.ly lir>dide

--

-' -.....

12

13

Cl~ , - CH -= C'H· ., HO · Prop!me • . l (Ann - MRJtovrnko1. HBr i Peroxt<k

addition)

Aq, KOH i.A CH3 - CH2 - <'Hi - OH ,.._ __ (N~uc;'"'"-loop-hi-.b-. r;:-

CH3-CH2-CH;i - Br I - fl.mm<l(lll)Jl:Anl!

I - Proplrlol

OH I

CH3 - CH - CH:i

1sopropyl .J cohol

C'l

(OxHlauon)

Cl

substrt111ionl

0 II

CH~-C-CHJ

Prop1111QnC

N•OI 1 (lodofomu•"tion)

Cl Cl

6 HNO:J I HiS0-1 ¢ ... Q &NO: t Nitration)

N02 ChlorobenzMe NC>i p .. ChJ0t0nittobeft2ene "' - Chloronitroben:rene o - Chloronitrobe11un~

(Major product)

¢ (ilNIOH,4l3K . 0 -,-ii)_dj ___ l E-.a---- . y

NOz

141'- C 1IQroni hobcn:z:tne

NO?

11 -1'.itrophi?r.ol I .·

. . •. 197

15

CHt - CK-~ .... HBr ,. .. ~.,

( .\nti-Marlowiko\. l HHr I Pemrirte • :Mit11)11)

C'H.1 CH. CH~ Br

l - Brnmcprcpar.e

Q4) How the following conversions can be carried out?

(i) Chloro ethane to butane

(ii)Benzene to diphenyl

(iii) tert·Butyl bromide to isobutyl bromide

(iv) Aniline to phenylisocyanide

~ 2 N~l l

16

Br I

IH~ - · (' ·- f.H I · I ( Dchy 1lroh 11losen+1rio n)

Br

KOii {ale) I A

CH· - C'H · CH, ·- Br. .. I -C'H3

17 fot But~ lbr(Jniid~

lsobu1yl bromide

198

Br

r.H-_~-CH, KOH {lk) 10 .,.

I (Mydl'Ulalogcn~n) 8r

19

crBr Br2 J Fe8r3 • lNa I dry ahet

(Firn g reaclioo)

~I

C II -. f\oi -· CH! -;- Dr

LH~

lsobutyl bromide

ALCOHOLS PHENOLS AND ETHERS

Family Functional group Example

Alcohol R-0-H CH30H methanol

Phenol Ar-0-H

Ether -f-19-f-o

me thylethcrCH:: OCH :;

Aldehyde -CHO Acetaldehyde C H3C.HO

Ketone -C -C-C- Acetone CH:;COCH> 1 11 I

0 0

Carboxylic acid -~-0-H

199

Ester

Am.ide

Acid Anhvdride ,

Acid chloride

IUPAC Name

CH3 - 0 - CH - CH3 I

CH3

H 0 -~ -O-t - H

I H

-~-N-H I H

0

- 1~-o-1t-o

-C-X I{

Ester Cfu - COOCH3

Methyl / acetate .

CfuCOOCOCR; acetic anhydride

acetyl chloride

CH3 -~-d

1- Methoxypropane

Methoxy benzene

[Anisole]

1- Phenoxy heptanes

2- Methoxy propane

2- ethoxy -1, 1- dimethyl cyclohexane

200

OH Benzene - 1,2 - diol •

2,5 - Dimethyl phenol

OH

CH:i - O H

CH:1 - CH41 - Clil - OH CH,- CH- CH}

I OH

CH:1 . , CH3 - CH1 - CH~ - OH

CH,- CH - CH1 - CH" I OH

CH., ·· CH - CH1 - CH, I 011

Cll1

I c11 ... -cr- ou

CH.

Clll- CJI - CJJ~ I ' I I on OH OH

CH3

{1) CH3 - CH - CH- 6-cfu I I I Cll~ OH CH3

2 ,2 ,4-Tri methylpentan-3-ol

Me thanol Propan- 1-ol

Propan-2 -ol

Bu Lan-I ~oJ

But~n -2-ol

2-:Mcthylpropa n- 1-o l

2 -MethylpnJp..tn · 2 -ol

Propane -1 2 . 3 -trlol

{ii} H3C- CH - CH2- CH- CH- CIT,- CJ I...

I I I • . 011 OH C1HE,

5-Ethylheptane-2, 4-diol

201

IUPAC names of phenols

0 OH CH.~ CH3

6 &OH 0 ,,.?.

OH

Phenol 2 · MC't hyl µhe11 ol 3 -Mcthylphenol

or-1 OH

& OH -

,,.?. & OH

Uenzenc- l .2·di of Benzene-1.3-dlol

C H.,

~H C l I"

.? .:· .. [11m.;Lll'~11phenol

IUPAC names of some ethers

CH3

¢ OH

4 -Mcthylphenol

OH

¢ OH

Benzene-1. 4-dJol

• • , - ' "'•' ~-·.I :.. l. • • I '~·' ' ·~ ( • • • 13 '.I I j' .._I I • ' • ., , ~ .. • • • \....7 \ t r I I :._ .1. .. -; ..

'· ·.·.; #'!'·"< .:· ., ... ,, ·~ ., •

. 202

! J

l

. Compo~d . WPAC name

CH,OCH;\

~H!\OC.Ji,

CH3 0CH:C H~CHa

~HsOCH:s

CeJ-IsOlC~)e - Cffs

CH,0-CH-CH I '

CH3

c.Hs-0-CH,- CH,-?H-C~

CH3

C~- 0 - CH2 - CH2 - OC~

H9C CH:. 00C,H,

Methoxymethane

Ethoxyelha.ne

l-Me thoxypropane

Meth o.xybenzene (Anisole}

Ethoxybenzene

1-Phenoxyheptane

2-Me thoxyp ropane

3- Methylbuto.xybenzene

1.2-Dtme thoxyethane

2-Ethoxy-- l,1-dlmethylcydohexune

Name reaction

(1) Reimer Tiemann. Reaction - [See in haloalkanes]

(2) Transesteriflcation

(3) Williamson synthesis

(4) Kolbe reaction

(5) Friedel craft

Transesterification : When an ester treated with excess of another

alcohol [other than the one from which ester has been derived ] in

203

pre.sence of corresponding sod. Or pot. Alkoxide or an acid HiS04 I l--

as catalyst i.e. also cleavage by analcohol calcolysis

0 0

11 R - ~ - OR!il + Rill - 0 - H R - C - 08IB + Rill - OH

Williamson synthesis:- Reaction with alkyl halide with sodium alkoxide or

sod. Phenoxide called Williamson synthesis.

R - X + R 1 - 0 - Na --. R - 0 - RIB + NaX

.' •

+ Nal

Both simple and mixed ether can be produced.

Depending upon structure and cleavage of unsymmetrical ethers by halogen •

acid may occur either by SN2 or SN1 mechanism. ~ ;:i

CH3 373k I

e.g. (i) CH3- CH - 0 -- CH3 +HI ---

CH3

l

sni

CH3

I CH3 - I + CH3 - CH -OH

(3)CH3C--9 - CH3 + HI~ (CH3h - C - I +CH3 - OH , .

dH3

204

... ~

I • I <!!

"" j

) J ~ J

~ 1 l ~

j

-ti. _• r

2 koxide or .6'

,

-~~ oy 1alogen

~

I;

I"'- -- _ . ....,H . - .._,

" •

(i}

(ii)

79%

LIMITATIONS OF WILLIAMSON SYNTHESIS

CH3

I CH3-C-O-Na++

I. CH

CH3 -CHr Br CH3 I

CH 3 - C-Q.!...CHr- CH3 + ~

CH3 I

I

CH3 - CH - OCHi - CH :~

::: l 'k

Kolbe reaction • I

205

a

~ .... -

OH

6NaOH ONa

6 (1) co. (U) ff

OH

~COOH u 2-Hydroxyberuoic acid

(Salicylic acid)

Friedel craft reaction

OCH,

6+CH,CI OOCH~H

Anhyd. AlClJ ~ cs, ..

2-Methox:y­toluen.e (Minolr)

OCH, 6 + Cfl.COCI Anhyd. AJC~ OCHJ

OCOCH1

+ :::::...

Ethanoyl chloride

206

2-Methoxy· acetophenone

(M·lnor)

¢H, CH3

4-Methoxy­loluene (Major)

OH,

I :::::...

COCH.J

4-Melhoxy­acet.ophenone

(Major}

-~ -

~ -

• ..

DISTINCTION BETWEEN PAIR OF COMPOUNDS

') -When 1- ,2-, a ~d 3- alcohol treated w it h lucas reagent [con, HCL +an

. . hydrou s ZnC1J at room t emp

(i) If turbidity appears immediately alcohol is 3°.

(ii} If turbidity appears in five minutes alcoho·1 is2°.

(1ii) 1° alcohol does not react with L R. at room temp.

iii) All t hose compound like alcohol, aldehyde Ketones which on

oxidat ion giving CH3 - co· Group undergoes odoform test .

e.g. (i) CH3CH2(>H

(II) CHr CHO

{Il l) (CH3) - CH - OH

(IV) CH3- COCH3

iV) C6Hs - C()-{:H3

:VI) CH3 - CH- CH2 - CHr CH3 . I OH

(VI I) CH3 - C - CHr CH2 - CH3

II 0

' 207

Important mechanism

(i) Hydration of alkenes

(ii}

(iii}

(iv}

.. + H-0-H+H .. .. ~

H-0-H +

H

H b H ---. +

208

) c::; c ::= + "20 <H'> :::::c -c~ I I

H? OH

CHaCH=CH2+ H20 <H' > C~-CH-CH:s I 01-1

e mechanism of the reaction involves the following three s teps: Step 1: Protonatlon of aJkene to fonn carbocatlon by electrophilic

attack of H30•. H20 + tt• ~ H3o•

~ H :::::c = c :::: + Hi~{-H < >

H I + .,,, -9- c, +H:iQ

Step 2: Nucleophilic attack of waler on carbocatlon.

H -~ H H I ~...... . ~ ~. ~ I I I + -c- c , + "20 ~ - C - C- 0 - H I • • I T

Step 3: Dcprotonatton to form ~ alcohol .. H H ~ H :OH I I I+ .j ~. I I •

-C- C- 0. - H + H 0 ~ - C1

- C- + H 0 I l V 1

• • l " ··

Important reaction

100°C / 373 K

413 K

C~3- CH2 - OH -----~----­

CH3

433 T0444 K

209

•

(2) Preparation of phenol from Cumene·

Cumcne Cumene hydroperoxide

(3) Preparation of aspirin and salol

COOH COOIJ

~011 H+ ~OCOCH3 u + (CJ·I3C0)20 --+ u Salicylic acid Acelylsalicyl1c acid

(Asptrin}

Explain phenol is acidic?

Phenpxide ion is resonance stabilised

·J) : QC ,

•

+ CH,COOH

If electron with drawing group are attached into the benzene ring it enchance acidic

·character and vice versa.

2,4,6 trinitrophenol > 2,4, dinitrophenol > 4-nitrophenol > phenol

210

·'·

Phenol > m- cresol > P cresol > O cresol

m-methoxyphenol >phenol> 0 methoxy phenol> P methoxy phenol.

• 0 chloro phenol> 0 bromophenol > 0 iodo phenol> 0 fluoro phenol

FORMATION OF PICRIC ACID

(I)

OH

Cone . HN03

N02 2, 4 ,..6-ni.nitmphen<:)L

(Pit.:ri4.; ac.;~<l)

OH Br Br

Br

2,4,6 tribromo phe'nol {white plot)

{I) Phenol gives violet colour with fec'3 solution .

211

"

PREPARATION OF 1°,2°,3° ALCOHOLS ·,

< HCHO + R Mg x R-CH20H . \ 1° ale . ~ .. ~ CH3CHO + R Mg x R

R )cHOH -r I 2° ale

... CH3

R --C- OH 3° ale

R

CONCEPTUAL QUESTIONS

Ql) Preparation of ethers by acid dehydration of secondry or 3° a1cohols is not a

suitable method?

Ans:- The formation of ethefS-by dehydration of alcohol is a bimolecu lar reaction (SN2)

group is hindered. as a result elimination dominates substitution as 3° carbocation is ]

more stable. Hence in place of others, alkenes are formed.

C-OH H,so •• CH3 > CON. CH3

Q2) Phenols do not give protonation reactions readily. Why?

Ans:- The lone pair on oxygen of O~H :in phenol is being shared with benzene ring

~hrough resonance.Thus,lone pair is not fully present on oxygen and hence phenols do

not undergo protonatian r~ac;~ions.. .· :

r. 212

;·

l , 1 ~ ~ ~ ] ~ l ~ ~

-----

03) Ortho· nltrophenol is more acidic than ortho -methoxy phenol? why?

Ans:- N02 group is electron with drawing which increases acidic charcter due to easily ease

REASONING QUESTIONS

01. Explain why propanol has higher boiling point than that of the hydrocarbon,

butane?

Ans . The molecules of Butane are held together by weak van der Waal's Forces of attraction

while those of propanol are held together by stronger intermolecular hydrogen bonding.

02. Alcohols are comparatively more soluble in water than hydrocarbons of

comparable molecular masses. Explain this fact.

Ans. Alcohols can form hydrogen bonds with water and break the hydrogen bonds already

existing between water molecules Therefore they are soluble in water. Whereas hydrocarbons

cannot form hydrogen bonds with water and hence are insoluble in water.

Q3 . While separating a mixture of ortho and para nitrophenols by steam distillation,

name the isomer which will be steam volatile. Give reason.

ANS. 0-nitrophenol is steam volatile due to intramolecular hydrogen bonding and hence can

be separated by steam distillation from p-nitrophenol which is not steam volatile because of

inter-molecular hydrogen bonding.

Q4. Explain why Is ortho nltrophenol more acidic than ortho methoxyphenol?

o - Nnrophenol

ANS. ' . ' . .- ... · ,, ... ,. ...

The nitro-group is an electron-withdrawing group. The presence.of this group in the ortho

: osition decreases the electron density in the 0-H bond . As a result, it is easier to lose a

::::ro1on. Also.the o-nitrophenoxide ion formed after the loss of proton is stabilized by resonance. 213

r I

r

Hence,ortho-nitrophenol is stronger acid.On the other hand, methoxy group is an electron­

releasing group. Thus ,it increases the electron density in the 0-H bond and hence, the proton

cannot be given out easily. Therefor ortho-nitrophenol is more acidic than ortho­

methoxyphenol .

05. Preparation of ethers by acid dehydration of secondary or tertiary alcohols is not a

suitable method. Give reason.

ANS. The formation of ethers by dehydration of alcohol is a bimolecular reaction (SN)2

involving the attack of an alcohol molecule on a protonated alcohol molecule. In the method, the

alkyl group should be unhindered. In case of secondary or tertiary alcohols, the alkyl group is

hindered. As a result, elimination dominates substitution.

06. What is meant by hydroboration~oxidation reaction? Illustrate it with an example.

ANS. Diborane (BH3)z reacts with alkenes to give trialkyl boranes as addition product. This is

o:<'u ised to alcohol by hydrogen peroxide in the presence

of aqueous sodi.um hydroxide.

C l-L,-CH=CHa + (H- Dl-12)z ~ CH:s-CH-CH, I I

CJf1-CH=CH 2

3CI-t,-CHi-CHl-OH + B(OH).,

Propan-1 ·ol

H BH.a

! CH_,-CH=CH1

(CH 1-CH'2-CH .J,BH

\... I · r •,$ •' !

07. Give the equations of reactions for the preparation of phenol from cumene.

Ans.

214

Cumcne Cumene bydropemldde

. Q8. Write chemical reaction for the preparation of phenol fron1 chlorobenzene.

•

Ans. Chlorobenzene is fused with NaOH at 623K and 320 atn1ospheric pressurf.:. Phenol is obtained by acidification of sodium phenoxide so produced.

Cl 6Na•· OH

6+NaOH 623K 6~ HCl 300atm ..-9 6

09. How is aspirin (Acetylsalicy1ic acid) prepared from salicytlc acid? Ans.

Acetylation of salicylic acid produces aspirin.

COOH COOII

6 011 H+ 60COCII~ + (C~C0)20--+ I

~

Salicylic acid AcetylcsalicyHc acid (/\spirin)

010. Which out of propan-1-ol and propan-2-ol is stronger acid? Ans.

Propan-1-ol is stronger acid than propan-2-ol . The acidic strength of alcohols is in the order

10>20>30_

011. What is denaturatlon of an alcohol?

Ans. The commercial alcohol is made unfit for drinking by mixing in it some copper sulphate

(to give it a colour) and pyridine (a foul smelling liquid}. It is known as denaturation of alcohol.

215

:

ANS. Dimethoxymethane

013. Diethyl ether does not react with sodium. Explain.

ANS. Diethyl ether does not contain any active hydrogen.

2 MARKS OUESJIONS

01 . Give two reactions that show the acidic nature of phenol. Compare acidity of phenol

with that of ethanol.

ANS. The acidic nature of phenol can be represented by the following two reactions: (i) Phenol

reacts -..vith sodium to give sodium phenoxide, liberating H2•

011 ONa

0 0 I + N1 ~ + THi

( Phenol Sodium phenoicido

(ii) Phenol reacts with sodium hydroxide to give sodium phenoxide and water as by·

products

The acidity of phenol is more than that of ethanol. This is because after

losing a proton, the phenoxide ion undergoes resonance and gets

stabilized whereas ethoxide ion does not.

216

-

•

Q2. How does phenol react with dilute and cone. HN03 ?

ANS. (i) With dilute nitric acid at low temperature (298 K), phenol yields a mixture of

ortho

OH OH

6 -Dll_u_te_H_N_o_, -ON02

+

o-Nttrophenol

Of I

¢ N02

p-Nltrophenol

and para nitrophenols. (ii) With concentrated nitric acid, phenol is converted to 2,4,6-

trinitrophenol. The product is commonly known as picric acid.

OH 6 Conc. HNO,

' .

OH

~, Q.iN~NOz ~

NO,. 2 , 4 , 6-'Il1nit.mphenol

(Picr1c a cid )

.. ' ~ ~

• ... ~j ; ..

217

0 3. How does phenol react with Br2 in CS2 and Bromine water?

ANS. (I) When the reaction is carried out in solvents of low polarity such as CHC'3 or

CS2 and at low temperature, monobromophenols are formed.

OH OH OH

6 (Jar ¢ Br2 in C52 t + 273 K

Br Minor Major

liii) When phenol is treated with bromine water, 2,4,6-tribromophenol is formed as

white precipitate.

OH

6:.... 1+ "' 3 Br~ --~>

Br Br

Br 2 ,4,6-Tl1bromophenol

04. How do you account for the fact that unlike phenol, 2, 4-dlnitrophenol and 2, 4, 6·

trinitrophenol are soluble in aqueous sol~tion of sodl~m ccirbonate? ' ·" 'l • . ' • • • • . • '\ •

ANS. 2, 4-Dinitrophenol and 2, 4, 6-trinitrophenol are str<;>nger a~ids then carbonic acid .. . . '

{H2C03) due to the presence of electron withdrawing- N02 groups. Hence, they react with

Na2C03 to form their corresponding salts and dissolve in aq. Na2C03 solution.

0 5 . ( i) Why is the Dipole moment of methanol higher than that of phenol? (ii} . Explain

why phenols do not undergo substitution of the -Oji group like alcohols.

218

t .

ANS. {i) Due to electron withdrawing effect of phenyl group, the C-0 bond in phenol is less

polar, whereas in case of methanol the methyl group has electron releasing effect and hence

C-0 bond in it is more polar.

(ii) C-0 bond in phenols has partial double bond character due to resonance and hence is.

difficult to cleave.

06. Account for the following

a. Boiling point of the C2HsOH is more than that of C2HsCI

b. The solubility of alcohols in water decreases with increase in molecular mass.

ANS. a. Because of hydrogen bonding.

b. With increase in molecular mass the non-polar alkyl group becomes more predominant.

07. Answer the following

a. What is the order of reactivity of 10, 20 and 30 alcohols with sodium metal?

b. How will you account for the solubility of lower alcohols in water?

ANS: a. 10>20>30.

b. Here-OH group is predominant and the alcohol molecules can form hydrogen bonds with

water molecules.

08. Give reasons:

!)Nitration of phenol gives ortho- and para- products only.

ii)Why do alcohols have higher boiling points than the haloalkanes of the same

molecular mass?

ANS (1} -OH group increases the electron density more at ortho and para positions through

. its electron releasing resonance· effeet.

(2) Alcohols are capable of for ming intermolecular H-bonds.

09. Account for the following:

I) Phenols has a smaller dipole moment than methanol t .. • ')... • •

II) Phenols do not g ive p rot ohaOon teactfons readlly.

219

r.

ANS. (a). In ph~nol the electron withdrawing inductive effect of -OH group is opposed by

electron releasing the resonance effect of -OH.

(b). The lone pair on oxygen of -OH in phenol is being shared with benzene ring through

resonance. Thus, lone pair is not fully present on oxygen and hence phenols do not undergo

protonation reactions.

0 10. Explain the fact that in aryl alkyl ethers

(i) The alkoxy group activates the benzene ring towards electrophilic substitution and

(ii) It directs the incoming substituents to ortho and para positions in be.nzene ring.

:o-R

0 ANS. ( i) Aly J alkyl et.h<1r.

In aryl alkyl ethers, due to the +R effect of the alkoxy group, the electron density in the benz

ring increases as shown in the following resonance structure.

Thus, benzene is activated towards electrophilic substitution by the alkoxy group.

(ii) It can also be observed from the resonance structures that the electron density

increases more at the ortho and para positions than at the meta position. As a result,

incoming substituents are directed to the ortho and para positions in the benzene .

220

--L --.... -..

3 MARKS QUESTIONS

01 . How are primary. secondary and tertiary alcohols prepared from Grignard

Reagents?

ANS.

n· R' H,O I

H.-CH-OMgX 1110 > R-i; i! · OH + Mg{OH}X f {C' l fO + R'MgX

R ' £<' I

RCOR + R' MgX I

R-(--OMgX R-C - OH + Mg(OH)X I .

R R

The reaction produces a primary alcohol with methanal, a secondary alcohol with other

aldehydes and tertiary alcohol with ketones.

02. Give the equations of oxidation of primary, secondary and tertiary alcohols by Cu

at 573 K.

ANS.

Cu RCI l:~C)l r RCI JO

573 K

H.-CH-R' Cu I 573K OH

CII CH., I " I 3 Cu

Cl~- (f - 0 1 I C l I.1 - C =Cl I:!

C 573K

11:-t

03. Give equations of the following reactions:

1.fi Oxidation of propan-1-ol with alkaline KMn04 solution.

'!i1 Bromine in CS2 with phenol.

:"iii) Di lute HN03 with phenol.

221

·' t

-

CH.CH,CH .. OH tt1kK1tl'JC.), )CH3CH~COOH

{ Propan-~ -ol. Propanoic ac id

8 1·-. in CS-. - -.. 273 R

?henol

OH

+

r

OH

I ~Dr

~

r- - bronop•enol o - Bnim.oph•ol (Major! (Minar)

O JI OH 6 d•lu" HNO,

04. Show how will you synthesize:

(i) 1-phenylethanol from a suitable alkene.

(ii) (ii) cyclohexylmethanol using an alkyl halide by an SN2 reaction.

(iii) (iii) pentan-1-ol using a suitable alkyl halide?

•

ANS. (i) By acid-catalyzed hydration of ethylbenzene (styrene), 1-phenylethanol can be

synthesized.

I - phe.y ~not

222

(ii) When chloromethylcyclohexane is treated with sodium hydroxide, cyclohexylrnethanol is

obtained.

6Ctti 0

1

11

... N .c'l

C ydnh a.,.-y l m .,lhanol

(iv) When 1-chloropentane is treated with NaOH, pentan-1-ol is produced .

l .Chlor-0pentane Pantan-l-01

05. How are the following conversions carried out?

(i)Propene - Propan-2-ol

(ii} Benzyl chloride - Benzyl alcohol

(iii} Ethyl magnesium chloride - Propan-1-ol.

ANS. {i)lf propene is allowed to react with water in the presence of an acid as a catalyst, then

propan-2-ol is obtained.

CH,-CH = CH; + H!O H1"' === CH, - CH - CH~ . I .~

OH

Propene Propan - 2 - ol

(ii) If benzyl chloride is treated with NaOH (followed by acidification) then benzyl alcohol is

produced.

CH4 C1

6· NaOH • - HCI

Bsl:zyl chlon d 6

(iii}When ethyl magnesium chioride is treated with methanol, an adduct is the produced which

gives propan -1-ol on hydrolysis.

223

c=O-+ C: :H5-M~CI ---- ( ~ H "- ~H~- 6:\t1:CJ I~/ CoH~

06.

(i)

(ii)

A.Jdw:t

l\.·l~(OJl) CI t- C' _;H~- 011

Po «fl.la> - I u l

Name the reagents used in the following reactions:

Oxidation of a primary alcohol to carboxylic acid.

(ii) Oxidation of a primary alcohol to aldehyde.

t !l:} Bro mi nation of phenol to 2,4,6-tribromophenol.

ANS. (i) Acidified potassium permanganate

(ii) Pyridinium chlorochromate {PCC)

(iii) Bromine water

•

07. How is 1-propoxypropane synthesised from propan-1-ol? Write mechanism

this reaction.

ANS. 1-propoxypropane can be synthesized from propan-1-ol by dehydration. Propan-1

ol undergoes dehydration in the presence of protic acids (such as H2S04, H3PQ4) to give 1

propoxypropane.

2CH 1CH~CH~ -OH

Propane-- 1-ol

H' --• CH3CH2CHi-O-CHlCH2C.H3

1-Propoxypropane

The mechanism of this reaction involves t.~~Jqg~m,qg~J~f~~~ij~;:.: · , ., :

Step 1 : Protonation

H Cll.lCll1CI 12 - (}-117

----. C'll3Cll,CH"'-o+-HJ .. ,, .... .. , .. l,opan - I - ol

224

Step 2: Nucleophilic attack.

•• ri'iou_ / H + n 1.cn.c11, - c: • cn3 - Clh ~ cH., Lo ____.. cH ~C'H .,CH., - o - cH-cH ... cH, . -' - . I ~ -- \_ H . • • I - .

H I I +

l-hO

Step 3: Deprotonation

... n1,n1ic11 . -~o-cn\(1t,CJ h --i••CI ~_,n •~nl_, - o- <:1 1~c11~r11 i + ir" - - - r..I - - - - -

H I Prnpoxypropane

08. Write the equation of the reaction of hydrogen iodide with :

(i) 1-propoxypropane (ii) Methoxybenzene and (iii) Benzyl ethyl ether

ANS. (i)

C2H5CH~ -O - CH~C2H~ -. Hl mi:.> CH_1CH2CHi - OH+CH_lCH~CH ! -- I

(ii)

{iii)

J. P ropoxypropane Propan- l-ol I - Iod opropane

OC'H OH

6' · 1 11 -~ 6 + CH3 - I

J\·tcthoxy~nzone Phenol lodomethane

CH1- 0 - C2H5 CH, I

6·w-~6 Benzyl ethyl edict

5 MARKS QUESTIONS , . ~ . . : (

Beru:yt iodid~ Ethanol

01. Write equations of the following re~~tlons :

(i) Friedel-Crafts reaction:...alkylation of anisole. · ·

225

»

"I •,1,

-- ------

(ii) Nitration of anisole.

(iii) Bromination of anisole in ethanoic acid medium.

(iv) Friedel-Craft's acetylation of anisole.

(v)Reaction of phenol with Zn dust.

ANS. (i)

()C. H;

6 Ammie

Anhy<l.AlCh ... OhCI c:s2 - lit

A nis<'t"l ..:

Cll!

.# Med10x~'1oh.iene ~ !\.laJl)r)

••~so.1

llNl).1

Z ·- l"'•tf'"'>~ni!iole (!'\.i i.nor)

1- Merho\yto lutne: (Minor)

4 - Ni tro3JUt-ol" {l\.1Qf<tr)

~ OCH,

&·· a .

J> - Dron•oan is.ol~ (MoY<>r)

., - Nltroani.tK>le (Minor)

•

&OCH,+ ~K c;'I

.. \ ,, 1..,; )I ~ :i - l\.1<!Cho>cy -~cl.llo,:tunono

tM tr'l(.)I'")

226

°' - ""loethoxy - · accto>henU,C!'

( M111or)

OH

6 , O~ j + ZnO : I + Zn -----,7 ~

Na CH ONa+H., ,.---....;..;. __ "?' 2 11

NaH c H ONa+H., ---~---,- :z 0

___ P_C_.1 __ , C .,H1CI

Alcohol

2'27

. ' ~ . . ." .° I - .. ·.·• .·. · ..

;.,, ' "'.' . I .. ;

c~ r~t-~fvl, ~~;-(r-~v· n'~ F..:\~~R'{fJ1.\~( L¥n~t: .- ... -:>KUG:...;;; - These are r:.hsmical3 of ~ •YrV f'l"t<.)lecul,"l< n i~2- {·i Ofr-50\Jy) "Which when consumed interact \;il'lih molecl!\<:r .~rgets i . 0. cflrbnhydrate, proteins, n f1\ds, nucleic ac;,d m ~(; hr\ng about biok1g\C?,\ r~sponstC. \f bio\ogicii.1 resoo n::; e t:; :. ~ L -s :- ~~po ~.Hie tt1B)i cire (~~ ~'t=;\! rnedtc1th:.: . ~·~·,ey ars ~JG~O f~or ~f1g~ .~ \tC·~~is 1 nrevBnfion t~nd tc,·;at -rrent cf d~.S€;7ise... · if ( ify ~~ r-<: ta!;;:en ii 1 higJ1 dose t.h an re.cr;mmeonded ~ i : ;.c, ;1 ~fH>v -l~ci <is ;~c.isu n. · Ct t~~rnuthe18py ivi;~~M; using chernica! for treatme11·i c.\' dis(;fi$0 . •

CLASSIFICATION OF DRUGS !Jrl.!gs can be c!nssi11ed on ttie foi!owina basis:

a! ~~!am1a.:~o:ogicai !::lfeci - This-is classification G! i!~e. r:trugs on tJ"1,~ ~xfi;~ c-.r eff;:}cl lhe dw9s can cause. E.;J . .-.nt1;.ry ;-e:1c dru\JS - brings c~cv...-n tevr:!r of th\~ body_ E.9 . parac~tsmc~, P~l~:nac.-:-tin, aspirin . An~lQ~sic ~rug - pain reUever e .g. Analgesic morphine (narcotic drug) Ant1mK:rob1ilf drug - kills germs e.g. ar:tiseµUc, antibiotic disinfectant

b) Drug Action - drug when consumed act 011 en:cyrne or receptor c) Chemlcal Struc\ure - drug Vlrith same structure has same sc..1ion d) Molecular Target Omg Effect- Molecular target may~ ~hydrate, protein, lipids. nucleic acid.

2:1,:?.YMI.'.: - They are g!obular prote:ns which Cflta.lys~ Hie bio cnerr;ic.a~ pf•ocess . .t\ct!On cf Enz~rne ·

1. Substrate rr.clecules are held at acuva site on enzyme so that it can 00 atfacked tty reagent. The substrate molecut•s is he!d at the ~ctive site by hydrogen bonding, dipole-dlpofe intereciion and Vonderwaal for<:e.

\ ~~ · ... , '

' ' I \ \ _ ........ . _j

' -·rt· ·· · ·c· \ , _ _. . . ~ : : ._ __ j

t_ .... ..__ ~

\. ___ j :-.. .) "'" j ,,..-.t ..

1. The s~.;;ond funciton of ~nzvrne ls io µrovi·Je h.H1ctional group which atta.dt \he substrate and CSil)' out dr6micai i·eact!on. -

Drug Interaction in Body Oiugs can interact trt br.:Xly either with (~) e.11;~.yrnc o.r (b) Receptor

A) DRUG - ENZVME tNTERACTION - Sometimes drugs set in body ~)'JI inhibiting the enzyme action at1d many dis~es are cured. En~yme. action can be inhibited by following method: . .

a) Competitive Inhibition - sometimes the drug binds on thct acute :$Ile of er:i.yrne~fiimty and hence the substrate not abie to bind on the aelive site.. ' ·

b) Sometimes drug.s bind an a specia! site of enzyrna called allosteric site and· <his i:;hariges the shape and siz.t:l of tne ~ctive site, so th~ substrate ._~annot bind on acth•e si\e

How dGes antidepressant acl? · Aiitidep~ssimt like lproniaz\o, Phenelzine inhibit 0n1yrn1;1 whic\·i metebolise neu~ .. i.ransmttter noradrenaline and nence neurotra'fismitter can activate the receptor for long timfl, tbus countering effect of depression. .

B) DRUG 1NETERACTION VVIJH RECEPTOR - the receptor are the protein embedded In the cell memorane oi the eel! wl1h their active site projeci.ing uLil.. When Chsmical messenger (rom neuron bind on 'the a~ve ~e °! receptor, tho n1essage is delivered within the cell and cell-peJfonns necessary function. The activa site 01

r~or are ve~ specJflc about chemical nie.s$enger. · Drugs interact with receptor ln two weys: . ·. .

a) ANTAGONIST - sometime$ drug bind on ihe &dive site of receptor and inhibit fundionmg ot ~ c.eU. b) AGONIST - sometime drugs bind on the active celi site of receptor and tnemsetves aciivata tM cE!ll to

funct.ior. . 0: How orugs like ctmetldine (teg~met). rarrtitidine (zentac) cure acidity? _ . . A. These are antihistamine which block receptor of stomach cell and not able to release. Ute acid m stoma:ti O: how does ?spirin act as pain felicver? · . · A: Aspi11n block. synthesis of prostagland\n whleh caus~s sw-emng and pain. Q: INhy antacids and 81\ti allergic do not interfere wtth too function of each otner? . . ·f _ \ri­A: As they bind on (lifferent receptor site i.e. anti alleftliC aru.gs cannot bind on recGp~o:· a.ctwe site meant .01 eintsc.""' ·

!)\fferent fy'pes of Clrugs . , . . , . . · '"°' ~r: 1) ANTACIDS - these are drugs wtJicr! are basic in nc.ture s.nd are used RI '-> ~te ae4dity ,n stomach wiu~ c ·

lead tr:> ulcer ~·n'\d pain e.g. NaHC03, ~g(OH)2. f;!(Ohh . . .. . _ '· ,. ,~ . ~ · Jr..s,;:;~s 11101.:; NaHC03 should not be prefalTed as r.. m3kes t11e medit!-111 n sio;r ·· ·.'·' ., 3_._, .~ a .. d stomach cell 10· ~ acid. · Mg(OH)2 , Al(OHh ar~ better as t71ey tic not increa:>e pH ab<Ne neutn/ . ~:,; . , .

2) A.r.ffi HlST,l\MINE - Anti Allergic ctr-Jgs -- H1~~8mine '1re chemicals rel€eSe(1 In t!ocly C<lU'S~:~ atlergie m~poose

- pasa: congest\on during ~~o\d _ . . .. . , . .. . _. -·· .. ,. .,, .,,., . ·n(·' ::-nd ·:.!Yf. /\.nt\hislam!ne like Bronptil!'::nn-.:;i;-;:i n\::1, ! erfer,a0 1n~ bmu <Jn !E!f;ep!or ' ' , .. · t. .. 11..1. 1t0 , enect of hl-·1~1.Toi ·

allergic response .

,.

3)

~)

;) ; ll

" •

. c-~~~'~ .. ~~l)F°.,C\U~'iA.("•"-~ ",.\."'~\;""!'\ 1r_'i _.a. ·~r:_:. ~. ,._• • •• .°';o: - ·'"l~~~·~'"''' . . . .. -~·:.;: ··~ . .. ·~ .• ., ·-·· .",:ti .. :;:--:1~;~")~ :. ' .. ·

TRAl,\tOUlU:?.:E:f.J,S - · Th!3~e .:iire :1Guro!ogl~I active; drugs used for trecttmefll of stress , c.nxlety, depresslofl enc oevere mental Gi~orde. e.o chlordiazepoxlde, meprobamate, equanll c,-ure tension . Baroituri~ acid deriv~tive •• Hypnottc (causes sleep) - equanil, Ner11blital, arnytal , seconal, tuminal - iuduce sll!ep nnd are co~stituents of sleeping pills_ . ANAl;-GSlC ·- :.ilu9~ whil'.;tl .are used to P!le, .. se pa1n e.g. aspirin, mar;ohir1::., h~rn:r., code\m~. Mo1phin'9, h0roin. cnd~.ne :.1re H~:-c.ot1<.: tm!tiictiva) r~nd used to g,;;t re:iof from ca1'dl:.lc ;.;aln. canc~r pc;in, ~est operalive pain. ANTIMIGFK>Bi.~1_ -· Thei1 ~ill N mt.ibit growth of mi<:roorganism 'w:-tic:h ~iusas <JiSt>.ase · AnUbiotic Antiseptic Disinff)c'i.ant

A} ANTISIO'flC •· TheM are ~tJstances which sre wholly or parUally made by c:·1emlr.a! ~ynthesl$ wlfch ir; t•Jw concentrati-Ofl inhibit ~rO\..f.b rof destrvy m icroorganism by lra.eNening 1n U'l&I•' r,;et&bolic a.:;tf'.tity

a B~ct.Si?.:,;cial - Antibiotic lflhtC'h k\ij bacteria e.Q. panlcillin, emino glyco.sides • 8ac:teriosfalic - A ntibl01ic wtl ich Inhibit growth Of bacteria e .g . chlorampt10r.icol. t<~tr&cycline, erythromycm

Spectrum of Antibiotic - r~nge of bacteria affected by antibiotic • . · . • B~oad spectrum antibiotic •• which can kill or lhhiblt growtn of wide rar.g& of 9rarn .,.ve or gram -ve b~cteria

e.g . ampic\\\in, en1oxlcillln, cl'llorai phenicol 0 Narrow spe~lrnm antibiotic - which can Ir.ill or lnhiblt either gram"'"""' <"f ~(arn -ve 1~0.e.•a e.g. penicil!!n • Limltad spectrum antlbiotlo - effective against cerl.ar1i oi!:;eas~ " r ff,:cc :.~ o r::,.r-;·nic,i:1

Q: What diseases can be cured by chlorampnenic()I? . A.; Typhoid, dysentery, uiinary Infection a: What are uses of Aspirin? . A: Antiyretic, analgestlc. rn.::ikino blood thin - c:void clotting <it bbld _: prevent h~srt attack. ,.

B) ANTISEPTIC - These !:!re <'.hemical np~U~j t-ti livmg tissua E~-~ wo:Jat1, \1l•:;e1 i ~, : ;a, .. ~~,,~ :·n.i .. ;;· ...... miGf oorganism

~.<; Dettol - mixture of ci1lorox:ylenol and terpineol T incture of iodine~ 2 -3% 1z soln In alcohol a11d water Bithional added to soap due to antiseptic prnp . 2 Cl/o pt\enol sol Boric &cid for eyes . . . .

C) OISINFECTAi'ITS - thes~ are chemicals usect to );.l\I microbes on i1on living 3lirfaoos e.g . 1% Prenol. A ppn i Cl2 solution

,;i: Name chcmical5 w t1!ci-: r.;ail ~\ct as antiseptic as w~!i as disil~fel.tan\s A Pl1enol .2% phenol ~ol" .•. amise\)tlc 1% phenol sol" - <.lisinft:ctaPt ANT:r.:ERTIUTY DRUG - 1.1sed tC· cont.rol p0P~!i3li0n . 8 ii1l1 C<Jnlrn! µiii h~'<S :;;rnih~I'~. ;:,:;trogen , proge:;tfO:'l. ~ ·~ rtl)11hindrone, bovcsti ci

SUMMA Of ME.OICINE ··--·----......-:· - NsHC03 ,Mg(OH}2, P1l~OHb. Zentac, Tt:gamet Cure aciditv -·--1

J -f ANT~ IDS -"2 ANTI JST AMi ... 3-· TRANQUlLIZE

NE R -· '"4'- ANALGESIC-- -

Anti aUeraic 8orn0hentramlne, Terfen3dine Menta\ disorder E.auanl11 Lumlnal, Nembutal, Seconal----·

Aspirin, Morptiine, 1".ieroln, cooein!._, Pain reliever ·------\

~ ANTIPYRETIC-

6 BROAD ANTIBIOTIC

7 NARROW

- Srinq down fever SPECTRUM

SPECTRUM ANTIBIOTIC

8 ANTI EP ! IC Kills germ on living

!TY DRUGS 9 ANTIFERllL I 0 ANTIPYRET tC

\ surface

~---J Brings do\vn fever

GHEMICAL IN FOOD Chemicals are used in food tCI

ftreserve for;d iviake it appe~!in~;

Paracetamol, Phenacetin Chlorampt1enioo1, Ampici!lin, Amoxydllin

Penictllin

and ter~neol), Tincture Dettol (Chloroxylenol .2%phenol. btothiVll9I, boric acid Northidrone, Novestro\ Paracetamol, Phenacetin -

--=J ___ . .,._ ... _ .. _

- impr0\/~1 ntt~ !itive V<"i!ll~ . . . , · ..•. •·. . . -. l- , .._ • . . ·, t di<,-;eSl'-~t'.:i ~:>j vvd;.t t-,HTIFICll,L SViJEcTEN;:f(S - thr~c;;e att! cnemh::-als ~h1ct-i c~suees Sw<;;o!"''"\·\' ~, - . ~ .. . ilL ,,.e~ .:.lm no -and \hrown •::i;.1i. as such ~k1~1 t!1?.t1s why they do not give ~ny en.&rgy . E..~ .

S2c-.chann . I • • · , 1-' ,. -- ~"" t11·~~"l"' "1,. -"•n» \;:,,-,!,., Asp ar'<A"in'le {l!::;i;;:d f('( !..'0 {, Oi1 rl1\S, co.~ f00u ...... ·-'~ - ..., "· -v~ "' . ' < I'' - • • . ....... o<"irer t c.~::r·u· ')~ • • • .... • 'I '·,,_ · ,,., .q::,• <·1.10~- •• ,,,., , , .... .,,v~ee,!;?l .tn . ., ..,u . Aiitain o -· a•,toldect &s 1t ts 20CID hn~e~ sw1;;..-.e1 .' •Q•' tt~·.,... . -• - · • •· · ·

oontrolled S1ncralose "·. us,;,d at n1gt1 h~mp as t>\2b!e a~ <:om• \n·~· t i:?1Y'\ f.i

:l: Why artifici?..! s·J11~?,t1~~1\.!: uSQO for di(,ci">6lic '.)&.i.if;nt? IV. Nl \hey do no\ Q'''" "'Y r;nor'd) • w! p100Ue<> >w;:eten•n•) etiW\. tho< ti<· , . ,,-ro ,o'•flV '" "'"' " no• •hW''"'" "''

b o d'§

SOPON!FICA T!DN Fal er oil "I· Nr.tOH -) S>:·HV ..;. g\y~..;~>::1

(R C.()•,:JN:·i}

CLC.ANIN<".:' ;.,;_.,,"fiO\\I ·:':'F $C•r\P . Tm d\rty c!otll I eo "" ,, ••• Oli doll' to wi1!C\ " '"si t< ,,<l•'.¥.lliC) "'".'"'' dirty c\l·I' IC "'~ •·u . . , "'"; "'''"'·"" ." "' ·:· . ' '•'". part 1._e · h> jro .' "' W.1 1>•rt OI SOB• <JOIS &tt.<1'100 ;c, d! sis';c ail<! hydropl1Uic ;»'" ·r '"' · ' ··""'" wtU« · 1 M <" >' '"' '·

pull~ nlJ'( i•' $0<lP so\1.1tion. " "'~ , .. ;" .. ::,\ - ._,,~ .. .. .

r· .. ""1: .. ~!::.~;.~· ·· ! • • ·• '~ l · )

·..... ,.,.("\('·· ~.r(· •

SGap does n<1t \.f<;)l l, \•\ \t~ud W1J\$r '~ \\ g~t prectp\ta~eG Oti\ !'.:"/ c:i ' ' MP./• \,; ~\~· ~ '~t:. ~<.:.r 7.RCOONa ·• C ., -) (R.CO~•nCa ~ -4· 2.Ns• Soc.fl S<-:um

~ \"'1011\c ·~>10rg•ny 11,01~oh"c ""'' l> ""'''"''· ''"' "" """""' '" ' · '""' ,,,,. ·' ••"-

\" ·~ ~ \ ~,-J !\\~)!' ~'.)\\iC oetergt;nts - T!1-:=.~~ ·:lo\.;,Hi,em'- do ';";Ot \1t>.V'5 \On5 In ltWlf (.<'"

2 11<.\ :,.'\~~r0ic ac\d

C: ""· <• 1:-io<i•.rJt !jdable detorg~\\~.$ - T~,,-: ::~; '~~',i::,· ·t}f:n1 '.· nm11=7.'

bro•1 '":~in<;; 1r1 I 1y('.1-ocaf't;\•!.