Chapter 13. Amines Chapter 13 Amines , Chemistry Class 12 | Page 11

( ix ) Oxidation Use of diffrent oxidising agents gives difTerent products . e . g .,
Separation of Mixture of Amines ( 1 °, 2 ° and 3 °)
( a ) Fractional distillation This method Is based on the boiling points of amines and is used satIsfactorily in Industry .
( b ) Hofmann ’ s methoOd Diethyloxalate is called Hofmann ’ s reagent with which mixture of amines is treated .
1 ° amine forms solid dialkyl oxamide ( CONHR ) 2 2 ° amine forms liquid dialkyl oxamlc ester ( CONR2-COOC2H5 ) 3 ° amlnes do not react
( c ) Hlnsberg ’ s method see . chemkal reactions .
Benzene Diazonium Chloride ( C6H5N2 + ; Cl - ) Preparation ( Diazotisation reaction )
The excess acid in diazotisation reaction is necessary to maintain proper acidic medium for the reaction and to prevent combination of diazonium salt formed with the undiazotised amine .
Diazonium salts are prepared and used in aqueous solutions because in solid state , they explode .