Organic Synthesis OCR A-level.

Alkene → Alkane

Hydrogenation.

150^oC

Ni catalyst

H2

Alkane → Haloalkane

Free radical substitution

Halogen

UV light

Alkene → Haloalkne

Electrophilic addition

HBr/HCl/HI

Haloalkane → Alcohol 

NaOH(aq) 

Heat under reflux 

Nucleophilic substitution 

Alcohol → Alkene

Elimination

H2SO4 (conc)

Heat under reflux

Alkene → Alcohol

Electrophilic addition

H3PO4

Steam

60atm

300^oC

Alcohol → Ketone

Secondary Alcohol

H2SO4 (aq)

Kr2Cr2O7 (excess)

heat under reflux

full oxidation

Alcohol → Aldehyde 

Partial oxidation of a primary alcohol 

H2SO4 (aq) 

K2Cr2O7 (limited)

Distil off immediately

Alcohol → Carboxylic acid

Full oxidation of a primary alcohol

K2Cr2O7 (excess)

H2SO4 (aq)

Heat under reflux

Alcohol → Haloalkane

NaBr (s)

Nucleophilic substitution

Heat under reflux

Conc H2SO4

Benzene → Nitrobenzene

Conc H2SO4

Conc HNO3

Reflux at 50 degrees C

Benzene → Chlorobenzene/ Bromobenzene 

AlCl3 (for chloro) 

FeBr3 (for Bromo) 

warm 

Friedel-Craft Alkylation

Alkyl Group with Chloro on (CH3Cl)

AlCl3

Friedel-Craft Acylation

AlCl3

ClCO - R (double bond Oxygen)

Carboxylic Acid → Acyl Chloride

SOCl2

Acyl Chloride → Carboxylic Acid

H2O

Carbonyl → Hydroxy nitrile

• NaCN

• H2SO4 (aq)

Acyl Chloride → Primary Amide

2 x NH3

Acyl Chloride → Secondary Amide

Primary Amine

Acyl Chloride → Ester

Alcohol

Ester → Carboxylate Salt and Alcohol

NaOH(aq)

Alkaline Hydrolysis

Haloalkane → Amine

NH3 (ethanolic)

Haloalkane → Nitrile

NaCN (ethanoic)

Nitrile → Amine

Hydrogen gas

Nickel Catalyst

150^oC

Carbonyl → Alcohol

NaBH4 (reducing agent)

Nitrobenzene → Phenylamine

Sn (Tin) catalyst

HCl(aq) Conc

reflux

Acid hydrolysis of polyamide (products and conditions)

Reactants:
6M HCl(aq)

Reflux 24hrs

Products:
diammonium salt

dicarboxylic acid

Alkaline Hydrolysis of a polyamide (products and reacts)

Reactants:

2M NaOH(aq)

Reflux

Products:

Diamine

Dicarboxylate salt

Alkaline Hydrolysis of a polyester (products and reactants)

Reactants:

2M NaOH (aq)

reflux

Products

dicarboxylate salt

diol

Acid Hydrolysis of a polyester (products and reactants)

Reactants:

2M HCl(aq)

reflux

Products:

Dicarboxylic acid

diol

Describe steps to purify an impure organic solution (liquid purification)

• Rough distillation

• separating funnel remove aqueous layer

• add Na2CO3 to remove any acid impurities - remove aqueous layer

• shake flask with distilled water to remove any salt formed in acid + carbonate reaction - remove aqueous layer

• Run organic layer into conical flask add drying agent (anhydrous calcium chloride) to remove water

• Accurate distillation - distil at exact boiling point of product

Describe steps to purify an impure organic solid (recrystalisation)

• Dissolve in the minimum amount of hot solvent

• hot filtration - collect filtrate

• cool slowly

• filter under reduced pressure

• wash crystals

• leave to dry

• Check purity - melting point should be sharp and not over a range. (if impure it will be over a range and slightly lower than expected).