18

no Lewis acid required because aniline is very reactive on its own.

2.8.

Benzene Diazonium Salts

2.8.1.Primary Aromatic Amines

General reaction scheme:

Mechanism

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NH2

NH2

Br

NH2

NHCOCH3

Br

Br

Br

vs

Br2/ xs

Br2

Ac2O

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NO2

R

NH2

R

NX
2

R

reduction

Sn / HCl
or
H2 / Pt

HCl / NaNO2

< 5oC

unstable
above 5oC

also H2SO4/ NaNO2
involves less nucleophilic counter ion HSO-
4