Flow Charts in Organic Chemistry

Std. XII FLOW CHARTS IN ORGANIC CHEMISTRY 2013 - 2014

STUDENT’S NAME : BRANCH :

BATCH :

ROLL NO :

COLLEGE :

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HALOALKANES & HALOARENES Preparation of Haloalkanes : 1) Halogenation R – H + Cl2 R – H + Br2 2) Hydrohalogentation CH2 = CH2 + HX * Addition of hydrogen halide on unsymmetrical alkane follows Markownikoff’s rule. (i.e. the negative part of reagent gets added to unsaturated carbon that carries lesser number of hydrogen). * Addition of HBr follows peroxide rule also. (Anti Markownikoff’s rule). 3) From Alcohols R – OH + HX R – OH + PX3 R – OH + PCl5 R – OH + SOCl2

D

–H2O

D

–H3PO3

D

–POCl3

Reflux Pyridine

R–X (Alkyl halide)

4) Borodine Hunsdiecker Reaction R – COOAg + Br2 5) Halogen exchange R – X¢ + NaI

(Finkelstein reaction)

–NaX¢

(swarts reaction)

–NaX¢

(X¢ = Cl, Br) R – X¢ + AgF

Mahesh Tutorial Science

2

HALOALKANES AND HALOARENES

Reaction of Haloalkanes :

1)

R¢ – COOAg (silver salt of acid)

2)

With alkali :-

–AgX

aq. NaOH

–NaX

aq. NaOH

–KX

moist Ag2O

–AgX

3)

R – X + Na metal (Wurtz synthesis)

4)

With alkoxide :R – ONa

Dry ether

–NaX

–NaX

(Williamson’s synthesis) R–X Alkyl halide

5)

6)

alc. NaCN

–NaX

alc. AgCN

–AgX

R – OH (alcohol) R – OH

R–R (alkane)

R–O–R (Ether)

R – CN (eyanide) R – NC (isocyanide)

Ammonia –HX

R – NH2 (Amine)

Grignards reagent :Mg (Dryether)

8)

R – OH

Cyanide :-

NH3

7)

R¢ – COOR (Ester)

R – Mg – X Alkyl magnesium halide

Elimination Reaction alc. KOH

–KX, – H2O

CH2 = CH2


3


Preparation of Haloarenes : 1) By electrophilic substitution CH3

CH3 + X2 Fe(dark) or FeCl3 or BCl3

–2HX

CH3 X

(X = Cl.Br)

+ X

2) Sandmeyer’s reaction

Cu2Cl2

NH2

(X – Cl)

X

N2+Cl– Cu2Br2

X = Br

Halo arene

KI

X=I


4


Reaction of Haloarenes : Cl

Halogenation : – + 2Cl2

anhydrous FeCl3

Cl Cl

– HCl

+ Cl (Major) Cl

Nitration :conc. H2SO4 D

HNO3

Cl NO2 +

–H2O

NO2 (Major) Sulphonation conc. H2SO4

Cl D

Cl SO3H

–H2O

Cl

+ SO3H (Major)

Chloro benzene

Cl CH3Cl

Anhydrous AlCl3

Cl CH3 +

–HCl

Friedel crafts

CH 3 (Major)

Cl CH3COCl

Anhydrous AlCl3

–HCl

Cl COCH3 + COCH 3 (Major)

Wurtz fittig reaction R – X + 2Na

R Dry ether

–2NaX

Alkyl benzene


ALCOHOLS, PHENOLS & ETHERS Preparation of Alcohols : 1) From alkyl halide R – X + NaOH(aq) R – X + KOH(aq) R – X + Ag2O(moist)

D

– NaX

D

– KX

D

– AgX

2) Alkenes CH2 = CH2

cold and conc. CH3 – CH2 H2SO4

HOH D

OSO3H (Addition of HOH follows Markownikoff’s Rule) Can undergo 1,2-methyl or 1,2-Hydride shift. Except ethanol, it gives 20 or 30 alcohol. CH3 – CH – CH2

B2H6

H2O2

(H3C – CH2 – CH2)3 B

OH–

(Anti-Markownikoff’s rule)

3) Reduction R – CHO (Aldehydes)

+H2 Ni D

O R–C–R

R – OH (Alcohol)

+H2

Ni D

+ 4 [H]

LiAlH4

– H2O

+ 4 [H]

LiAlH4

– R¢OH

(ketones)

O R – C – OH (Acids)

O R – C – OR¢ (Esters)

4) Grignards reagent H H – C = O + R – Mg – X

(10 alcohol)

H R – C = O + R – Mg – X

(20 alcohol)

O R – C – R + R – Mg – X

(30 alcohol)


6

ALCOHOLS, PHENOLS & ETHERS

Reaction of Alcohols : (10 > 20 > 30)

1) Metals : Na

–H2

K

–H2

Al

–H2

R-ONa R-OK (R-O)3Al

2) Esterification: R¢ - COOH

H+

–H2O

R¢-COOR

R¢ - COCl

Pyridine

–HCl

R¢-COOR (ester)

(R¢ - CO2)O

Pyridine

–R¢COOH

0

0

R¢-COOR

0

3) Hydrogen halides : (3 > 2 > 1 ) Anhyd. ZnCl2, D

10 HCl

R-OH (alcohol)

2

0

3

0

R-Cl

Anhyd. ZnCl2

R-Cl

Room Temp.

HBr

(10, 20, 30)

NaBr + H2SO4

HI

(10, 20, 30)

NaI + H3PO4

4) Phosphorus hlide and SOCl2 :

R-Cl (alkylhalide) R-Br R-I

PCl3

–H3PO3

PCl5

–HCl, –POCl3

SOCl2

–SO2, –HCl

PBr3

Red P. (Br2)

–H3PO3

PI3

Red P. (I2)

–H3PO3

R-CI R-CI R-CI R-Br R-I

5) Dehydration : (30 > 20 > 10) H3SO4

Al2O3

6) Oxidation : 10 2

10

95% H2SO4

443 K

20

60% H2SO4

373 K

30

20% H2SO4

363 K

10

623 K

20

523 K

30

423 K

Alkenes

Alkenes

(10 > 20 > 30) Aldehydes

0

Ketones

[O] [O]

Carboxylicacid Carboxylicacid (less carbon)


7


Preparation of Phenol :

1) From chlorobenzene :Cl

ONa HCl

NaOH, 300atm, 623 K (Dow’s process)

Cl + HOH

,

Ca3(PO4)2

698 K

(Rasching’s process)

2) From Benzene sulphonic acid SO3H

ONa

SO3Na NaOH – H2O

NaOH , 573 K – Na2SO3 , – H2O

HCl – NaCl

OH 3) From cumenc (isopropyl benzene) O – OH H3C

CH

CH3 + O2

cumene

Mn-naphthenate or Co-naphthenate Alkaline dil Na2CO3 at 403 K

Phenol

H3C – C – CH3 dil H2SO4 distillation – CH3COCH3

cumene hydroperoxide

(Commerical method) 4) Diazotisation Method

+ — N2Cl

NH2 NaNO2 + 2 HCl 273 – 278 K

Aniline

H2O + dil H2SO4 – NaCl – H2O

D

– HCl , N2

Benzene diazonium chloride


8

ALCOHOLS, PHENOLS & ETHERS Reactions of Phenol :

OH Br2 inCS2

OH Br

273 K

+

– HBr

Bromination

Br

OH Br

Br2 water (Redcolour) Room. Temp

Br (white ppt)

– HBr

Br OH

OH NO2

dil HNO3

+

– 2H2O

Nitration

NO2

OH O2N

conc. HNO3 conc. H2SO4

NO2 2, 4, 6 - Trinitrophenol (Picric acid)

– 3H2O

NO2 OH SO3H

conc. H2SO4 298 K – H2O

OH Sulphonation

OH conc. H2SO4 373 K – H2O

Phenol

SO3H Reimer - Tiemann Reaction ONa

ONa CHCl2

CHCl3 + NaOH

ONa CHO

CH(OH)2

2NaOH

ONa HCl

– H2O

CHO

– NaCl

Kolbe’s Reaction ONa NaOH

OH (i) CO2 +

(ii) H

COOH salicylic acid

With Zn dust Zn

+ ZnO

D

Benzene Oxidation K2Cr2O7

O

dil H2SO4


9


Preparation of Ethers : 1) From Alcohols R – OH + R – OH

conc. H2SO4 413 k

– H2O

(Acid catalysecl Dehydration)

R – OH + R – OH

Al2O3 513 – 523 k (catalytic dehydration)

– H2O

(Only with primary alcohols) Used for simple ethers. 2) Williamsons Synthesis (Labolatory method) R – X + Na – OR

D

–NaX

R–O–R ether

Used for simple as well as Mixed ethers.

3) From Alcohols and cliazomethane : R – OH + CH2N2

HBF4

–N2

Used to prepare alkylmethyl ether.


10


Reaction of Ether : With hydrogen Iodide (HI) cold HI

(simple ether)

cold HI

(mixed ether)

R – I + R – OH R – OH + R¢I

* If one alkyl group is 10 or 20. Lower alkyl group forms alkyl halide. (SN2) * If one alkyl group is 30. 30 alkyl halide is formed. (SN1). R – O – R¢ Ether R = R¢ = simple ether R ¹ R¢ = mixed ether

Hot HI

D

(simple ether)

–H2O

Hot HI

D

(mixed ether)

–H2O

2R–I R – I + R¢I

Hydrolysis H2O

dil H2SO4, Pressure

(simple ether)

H2O

dil H2SO4, Pressure

(simple ether)

R – OH + R¢ – OH OCH3

OCH3 Br

in CH3COOH

Br2

2R – OH

+ (Minor)

OCH3

CH3Cl . AlCl3 Friedel crafts

OCH3 CH3

Br (Major) OCH3 +

(Minor)

Anisole

CH3COCl . AlCl3

OCH3 COCH3

CH3 (Major) OCH3 +

(Minor)

conc. HNO3, H2SO4 (Nitration)

OCH3 NO2

COCH3 (Major) OCH3 + NO2


ALDEHYDES, KETONES & CARBOXYLIC ACID Aldehydes and Ketones Preparations :

O3 / H2O / Zn

C=C

H2O / HgSO4

–CºC–

Cl

aq. NaOH

C=C Cl (Geminal dihalide)

oxidation

CH – OH

PCC. or collin’s reagent

(10 – 20 alchol)

CH = O

(i)

R–CºN

R MgX

(Aldehyde or ketone)

+ (ii) H3O

O H2 / Pd + BaSO4

R / Ar – C – Cl

Rosenmund reduction

O –C–O O

D

C

Dry distillation

–C–O

ONLY ALDEHYDES : O R – C º N + 2(H)

SnCl2 / HCl H2O

+

R–C–H (Aldehyde)


12

ALDEHYDES, KETONES & CARBOXYLIC ACID

Aldehydes and Ketones Reactions :

– .. H – CN / OH cat.

OH C CN OH

R – MgX

(i)

C

(ii) H3O +

R OH

NaHSO3

C SO3Na OH

+

H2O/H

C OH

2 RO – H / H (– H2O)

CH = O (Aldehyde or ketone)

+

OR C

+

OR

H – O – CH2 H

H – O – CH2

+

(– H2O)

O – CH2 C O – CH2

aldol reaction

a, b – unsaturated

dil . NaOH

aldehydel ketone

..

H2N – Z

H

+

(– H2O) H2

Pd

or H

Zn – Hg

NH2 – NH2

LiAlH4

+

HCl

.. C=N–Z

CH – OH

CH2

KOH

CH2


13


Preparation of Carboxylic acids : 1) Oxidation

R – CH2 OH

K2Cr2O7/dil H2SO4

–

C6H5 R

Alkaline KMnO4

K2Cr2O7/dil H2SO4

R – CHO

COO K

+

dil HCl

2) Hydrolysis

(I) dil HCl

D

(ii) dil NaOH

D

R – CN

H–OH . HCl

R – CONH2 – NH4Cl

3) From Dry ice Dry ether

H-OH ,

dil HCl

R - COOH carboxylic acid

O = C = O + R – Mg - X (CO2)

4) From acyl chloride and acid anhydride H2O

, OH–

R – COCl

(R CO)2 O

H2O

5) From esters (by hydrolysis)

R – COOR¢

dil H2SO4

,

D–

– R¢ – OH


14

ALDEHYDES, KETONES & CARBOXYLIC ACID Reaction of Carboxylic acids : Reaction involving cleavage of O – H bond Na or NaOH or Na2CO3

R – COONa

Reaction involving cleavage of C – OH bond

(A)

(B)

(C)

(D) R-COOH R = alkyl or arul group

SOCl2

(D)

–SO2 , HCl

PCl3

D

–H3PO3

PCl5

D

–POCl3

formation of acyl chloride

R¢ OH

D

O ,

conc. H2SO4

–H2O

(formation of ester)

P2O5

D

,

R–C–O–R

(R – CO)2 O

(formation of anhydricle) NH2

R – CO – Cl

D

R – CO – NH2

Reactions involving – COOH group LiAlH4 , ether , H3O+ (formation of 10 alcohol , reduction)

NaOH , CaO , D

R – CH2 – OH

R–H

(Decarboxylation)

Substitution reactions in the hydrocarbon part (i) X3 , reaction P , (ii) H2O (Hell-volhard-zelinsky reaction)

R – CH – COOH X (a - halo carboxylic acid) COOH

conc. HNO3 , conc. H2SO4

Nitration (For aromatic acids)

NO2

(m – substituion)


15


PREPARATION AROMATIC ALDEHYDES : CH3

CrO2Cl2, CS2 H3O+

(Toluene)

CH3

Cl2 /hv

CHO

(Toluene)

(Benzaldehyde) CO, HCl Anhydrous AlCl3

(Benzene)

O H2

–C–Cl

Pd–BaSO4

(Benzoyl chloride)

AROMATIC KETONES : O CºN

Ph–Mg–Br / Dry ether H3O

C

+

(Benzophenone) O

O + CH3 – C – Cl

Anhydrous AlCl3

C – CH3

D

(Acetophenone)


Flow Charts in Organic Chemistry

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