NEW MATERIAL:Tetrazo compounds of formula I, wherein M is H, alkali metal; R1 is alkyl; R2 is alkoxy; R3, R4 are each alkyl, alkoxy; X is halogen, a group of formula II; R5, R6 are each H, SO3H, halogen, alkyl, alkoxy; R7 is H, alkyl.

USE: Dyes which dyes cellulosic fibers and nitrogen-contg. fibers and allows cellulosic fibers to be dyed under pH and dyeing conditions under which polyester fibers can be dyed by disperse dyes.

PREPARATION: 1mol of a compd. of formula III (wherein X1 is halogen) is condensed with 1mol of a compd. of formula IV to prepare a tetrazo compd. of formula V. The compd. of formula I, where X is a group of formula II, can be prepd. by condensing 1mol of a compd. of formula V.