organic reactions

alkane → haloalkane

free radical substitution

UV light

initiation, propagation termination

produces low yield of specific product - further substitution, substitution can occur at any point on the carbon chain, products other than desired product made

alkene → alkane

hydrogenation

423K

H2 / Ni catalyst

alkene → haloalkane

halogenation

electrophilic addition

room temperature

e.g. decolourisation of bromine water

halogen / hydrogen halide

if hydrogen halide, mixture of products made - major/minor products

alkene → alcohol

hydration

steam

H3PO4 catalyst

major/minor products if asymmetrical alkene

addition polymerisation

Ni catalyst

high temperature and pressure

alkene

primary alcohol → aldehyde

oxidation

K2Cr2O7/H+ (aq)

distillation

just enough oxidising agent

H2O as side product

primary alcohol → carboxylic acid

oxidation

K2Cr2O7/H+ (aq)

excess oxidising agent

reflux

H2O as side product

secondary alcohol → ketone

oxidation

K2Cr2O7/H+ (aq)

reflux

H2O as side product

alcohol → alkene

dehydration

reflux

conc sulfuric / phosphoric acid

alcohol → haloalkane

substitution

reflux

H2SO4 and NaX (forms hydrogen halide in situ)

H2O as side product

haloalkane → alcohol

nucleophilic substitution

source of OH - NaOH or H2O

reflux

speed of hydrolysis related to bond strength of C-X

• C-Cl stronger than C-I

radical substitution of ozone

initiation: CF2Cl2 → CF2Cl· + Cl·

propagation: Cl· + O3 → ClO· + O2

ClO· + O → Cl· + O2

overall: O3 + O → 2O2

benzene → nitrobenzene

nitration

electrophilic substitution

50°C for nitrobenzene, higher = further substitution

conc H2SO4 and conc HNO3

benzene → halobenzene

halogenation

electrophilic substitution

rtp

halogen carrier - AlCl3 or FeBr3

halogen

alkylation of benzene

electrophilic substitution

benzene + haloalkane

needs halogen carrier - AlCl3, FeBr3

acylation of benzene

electrophilic substitution

benzene + acyl chloride

halogen carrier - AlCl3, FeBr3

phenol → phenoxide ion

neutralisation of phenol

NaOH (needs strong base) as it is weak acid

halogenation of phenol

electrophilic substitution

room temperature

no halogen carrier needed - phenol less stable and more reactive

with Br2 - white ppt and bromine decolourised

nitration of phenol

electrophilic substitution

room temperature

dilute HNO3 - no need for H2SO4 catalyst

mixture of 2 isomers - 2 and 4 positions

bromination of phenylamine

electrophilic substitution

rapid - NH2 activates ring

substitutes at 2,4,6 positions

bromination of nitrobenzene

electrophilic substitution

slow reaction - NO2 deactivates the ring

needs halogen carrier and high temperature

carbonyl → alcohol

reduction

nucleophilic addition

NaBH4 = reducing agent

warmed in aq

aldehyde → primary alcohol

ketone → secondary alcohol

carbonyl → hydroxynitrile

reduction

nucleophilic addition

HCN - provided by NaCN and H2SO4 in reaction

increases carbon chain length

aldehyde → carboxylic acid

oxidation

reflux

K2Cr2O7/H+ (aq)

occurs during Tollen’s

redox / neutralisation of carboxylic acids

carboxylate salt produced

react with metals - metal disappears, effervescence of H2

react with carbonates - H2O and CO2 produced

react with metal oxides and alkalis - H2O produced

carboxylic acid → acyl chloride

acylation

fume cupboard needed

SOCl2

produces HCl (g) as side product

carboxylic acid + alcohol → ester

esterification

condensation reaction

conc H2SO4

warmed

H2O as side product

reversible reaction

acyl chloride + alcohol → ester

esterification

irreversible

HCl produced instead of H2O

no H2SO4 catalyst - acyl chlorides highly reactive

acyl chloride + phenol → ester

esterification

more reactive than carboxylic acid so can esterify phenol

acid anhydride + phenol → ester (phenyl alkanoate) + carboxylic acid

esterification

more reactive than carboxylic acid so can esterify phenol

slower reaction than acyl chloride

no toxic products produced

produces carboxylic acid too - other half of acid anhydride

2xcarboxylic acid → acid anhydride

condensation reaction - forms H2O

acyl chloride → carboxylic acid

reacted with water

violent reaction

fume cupboard - HCl(g) produced

acyl chloride → primary amide

ammonia

acyl chloride + 2NH3 → primary amide + NH4Cl

acyl chloride → secondary amide

primary amine

acyl chloride + 2xprimary amine → secondary amide + CH3NH3Cl

acid hydrolysis of esters

ester + water ⇄ carboxylic acid + alchol

reflux

water and dilute acid

reversible reaction

alkaline hydrolysis of esters

ester + base → carboxylate salt + alcohol

reflux

hydroxide ions - NaOH

irreversible

flood with H+ to get carboxylic acid

haloalkane → primary amine

excess ammonia (nucleophile)

ethanol as solvent

produces NaCl and H2O as side products (NaOH also used as base)

haloalkane + NH3 → alkylammoniumchloride

alkylammoniumchloride + NaOH → amine + NaOH + H2O

haloalkane → secondary amine

haloalkane + primary amine → dialkylammoniumchloride

dialkylammoniumchloride + NaOH → secondary amine + NaCl + H2O

further substitution can occur to make tertiary and quaternary amines by reacting with secondary and tertiary amines

nitrobenzene → phenylamine

reduction

reflux

HCl / Sn catalyst

amino acid + acid

forms salt - NH3+

amino acid + alkali

forms salt - COO-

and H2O

esterification of amino acids

heat

conc sulfuric acid catalyst

amino acid + alcohol → ester + H2O

condensation polymerisation

polyester or polyamide

removal of H2O or HCl

polyester - monomer with carboxylic acid and alcohol, or 2 monomers, one with dicarboxylic acid and one with diol

polyamide - monomer with carboxylic acid / acyl chloride and amine group, or 2 monomers, one with dicarboxylic acid / acyl chloride and one with diamine

hydrolysis of polyesters

hot acid (H+ / H2O) - COOH formed,

hot alkali - COO- formerd

hydrolysis of polyamides

hot acid (H+ / H2O) - NH3+ and COOH formed

hot alkali - COO- and NH2

haloalkane → nitrile

lengthen carbon chain

nucleophilic substitution

NaCN

ethanol as solvent

nitrile → amine

reduction

H2 / Ni catalyst

Nitrile → carboxylic acid

hydrolysis

dilute acid and water