Chem 18: Synthesis + Random Orgnaic

Edexclel A level

Carboxylic to Alcohol

LiAlH4, dry ether, then H2O (to protonate alkoxide)

Alcohol to Haloalkane (2 ways)

1) HX, conc. H2SO4 cat.

2) PCl5 (dry, rtp. Produces misty fumes of HCl)

Haloalkane to Amine

Nucleophilic substitution

Conc. NH3, in ethanol, heat in a sealed tube

Benzene to Benzene-aldehyde/ketone

Electrophilic substitution (acylation), acyl chloride, dry ether, AlCl3, reflux

Benzene to benzene with an alkane chain

Electrophilic substitution (alkylation), halogenoalkane, rtp, dry ether, AlCl3

Benzene to phenylamine

1) Nitration: Electrophilic substitution, conc. HNO3 + conc. H2SO4, reflux

2) Reduction: conc. HCl, Sn cat., reflux

Phenylketone/benzaldehyde to benzene ring+tertiary/secondary alcohol

Nucleophilic addition, Grignard reagent (R-MgBr), dry ether, then H2O

Acyl chloride + alcohol

= ester

nucleophilic addition-elimination reaction

Rtp

faster and more effective than esterification with carboxylic acids

HCl ???? Aq or gas byproduct

How to make a Grignard’s reagent

React Mg with Halogenoalkane in dry ether, reflux

How do reactions with Grignard reagets happen

R is delta negative in R-MgBr => R acts as a nucleophile

Haloalkane to alkene

Hot ethanolic NaOH

Alcohol to Alkene

Conc. H2SO4, 300*C

Alkene to Diol

+ cold, KMnO₄ in H2SO4

Alkene to dihalogenoalkane

X2

Carboxylic acid to Acyl Chloride

PCl5

PCl₅ Test

alcohols and also carboxylic acids, rapid reaction at rtp

Steamy white fumes of HCl gas

Dry blue litmus paper turns red then white (due to HCl and acidic chloride)

To tell between carboxylic acid and alcohol???

sodium metal or Na₂CO₃

C=O groups (carbonyls)

nucleophilic addition reactions

• The C=O bond is:
  

  • Polar: Carbon is δ⁺, oxygen is δ⁻

  • So nucleophiles (like CN⁻, H⁻, or H₂O) are attracted to the electrophilic carbon

• Exception:

  • C=O with a leaving group (like esters, acyl chlorides) → nucleophilic acyl substitution

Aldehyde to Hydroxynitrile??

Hydrogen cyanide (HCN)

• In aqueous KCN, Dilute H₂SO₄ (acts as acid to generate HCN in situ), Room temperature

Iodoform test

I₂ in the presence of alkali NaOH

• It identifies compounds that have a methyl group (–CH₃) attached to a carbonyl (C=O) or a secondary alcohol structure.