Studies on synthesis of 2-methyl-3,1-benzoxazine-4(4H)-one dyes and their application on nylon and polyester fibres

A series of 3-{4-[4-(4-arylazo)-benzenesulfonyl]phenyl}-2-methyl-3H-quinazolin-4-one derivatives (3) have been obtained by a reaction of a various coupling agent (a-g) with diazonium salt containing 4-oxo-quinazolin moiety (2). The diazonium salt 2 is obtained by the reaction of 4-(2-methyl-4-oxo-3-quinazolinyl)-4'-aminodiphenylsulfone with NaNO2 and HCl. The product is characterized by spectral and analytical data. Most of the tested compounds show promising dyeing properties.