organic synthesis

Question 1

Carbon-carbon bond formation

Answer 1

Important as they provide a way of creating new compounds with more carbon atoms

Question 2

Nitriles from haloalkanes

Answer 2

Formed by reacting haloalkanes with sodium cyanide (NaCN) or potassium cyanide in ethanol, in this reaction the length of the carbon chain increases. This is nucleophilic substitution. Possible reaction =CH3CH2Cl + KCN –> CH3CH2CN + KCl

Question 3

Nitriles from aldehydes and ketones

Answer 3

Aldehydes and ketones will with react with HCN. However, HCN is too poisonous to use so instead a mixture of NaCN and sulfuric acid is used, to improve safety and reaction rate
CH3COCH3 + HCN –> CH3C(OH)(CN)CH3

Question 4

Reduction of nitriles

Answer 4

Nitriles can be reduced to amines by reacting with hydrogen in the presence of a nickel catalyst
CH3CN + 2H2 –> CH3CH2NH2

Question 5

Hydrolyses of nitriles

Answer 5

Nitriles undergo hydrolyses to form carboxylic acids by heating with dilute aqueous acid i.e. HCl
CH3CN + 2H2O + HCl –> CH3COOH + NH4Cl

Question 6

Alkylation of benzene rings

Answer 6

Alkylation is a reaction which transfers an alkyl group from a haloalkane to a benzene ring. The catalyst AlCl3 is needed, HCl is also produced

Question 7

Alcylation of benzene rings

Answer 7

When a benzene ring reacts with an alcyl chloride in the presence of an aluminium chloride catalyst, a ketone is formed. HCl is also produced

Question 8

Nitriles to carboxylic acid

Answer 8

H2O, HCl, heat

Question 9

Acyl chloride to carboxylic acid

Answer 9

H2O

Question 10

Aldehyde/ketone to alcohol

Answer 10

NaBH4

Question 11

Alcohol to alkene

Answer 11

H2SO4 and heat

Question 12

Haloalkane to alcohol

Answer 12

NaOH (aq)

Question 13

Aldehyde/ketone to hydroxynitrile

Answer 13

NaCN(aq)/H+(aq)

Question 14

Haloalkane to amine

Answer 14

NH3 in ethanol

Question 15

Alcohol to haloalkane

Answer 15

Sodium halide and H2SO4

Question 16

Acyl chloride to secondary amide

Answer 16

Primary amine

Question 17

Acyl chloride to primary amide

Answer 17

NH3

Question 18

Alkene to alcohol

Answer 18

H2O (steam) / H3PO4

Question 19

Ester to carboxylate salt

Answer 19

Hot aqueous alkali

Question 20

Alkene to alkane

Answer 20

H2/Ni 150 degreese

Question 21

Ester to carboxylic acid

Answer 21

Hot aqueous acid

Question 22

Carboxylic acid to ester

Answer 22

Alcohol / conc. H2SO4

Question 23

Nitrile to amine

Answer 23

H2 / Ni

Question 24

Haloalkane to nitrile

Answer 24

NaCN or KCN in ethanol

Question 25

Alcohol to aldehyde

Answer 25

K2Cr2O7 / HSSO4 distil

Question 26

Alcohol to ester

Answer 26

Carboxylic acid / conc. H2SO4 or acid anhydride or acyl chloride

Question 27

Alcohol to carboxylic acid

Answer 27

K2Cr2O7 / H2SO4, reflux

Question 28

Alkane to haloalkane

Answer 28

Halogen, UV

Question 29

Acyl chloride to ester

Answer 29

Alcohol

Question 30

Carboxylic acid to acyl chloride

Answer 30

SOCl2

Question 31

Alkene to haloalkane

Answer 31

Hydrogen halide

Question 32

How do you prepare a solid substance to be tested

Answer 32

Dissolve 5 grams of the substance in the minimum amount of hot water whilst stirring. Then filter it to remove the debris