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DIAZOTISATION

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Conversion of primary amino group into diazo group using HNO2 (weak, unstable acid.So,

insitu prepared by reacting NaNO2 with aq solution of strong acidor) at 0 5 0C is known asdiazotization (or) Griess reaction.

A) Aliphatic :

Aliphatic diazonium compounds readily decompose even at low temperature and lose nitrogen to

form carbocations, which produce a mixture of alkenes ( By removal of proton), alcohols ( by reacting

with H2O) and alkyl halides (by reacting with halide ion)

RNH2 + NaNO2 +2HX

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B) Aromatic :

Arene diazonium salts are also unstable , but still far more stable than aliphaticdiazonium salts. They do not decompose , if the temperature of the reaction is kept below 50c

Ar NH + NaNO + 2 HX Ar N N X + NaX + 2H O2 2 2

Mech: