NEW MATERIAL:Compounds of formula I wherein R1 is a 1W14C alkyl which may be interrupted by 1W5 oxygen atoms, cycloalkyl, aryl, etc.; R2 is H, F, Cl, CH3, CN, etc.; R3WR5 are each H, F, Cl, CH3, etc.; Q2 and R3, Q3 and R4 or Q4 and R5 may be each a group of formula II or III which can form a ring when combined together at 2- and 3-positions of the benzene ring; n is 0, 1; X is a 1W14C alkoxy which may be interrupted by 1W5C oxygen atoms, cycloalkyloxy, etc.

EXAMPLE: Compound of formula IV.

USE: Red dyestuff for guest-host color display, synthetic resins, synthetic fibers.

PREPARATION: An aminocinnamic acid derivative of formula V is diazotized and then coupled with a compd. of formula VI. The product is hydrolyzed to obtain a monoazo compd. of formula VII, which is then diazotized and coupled with a compd. of formula VIII (wherein Y is hydroxy, etc.). The product is alkylated to produce the compd. of formula IX.