AZO COMPOUND, PREPARATION THEREOF AND USE THEREOF AS DYE

PROBLEM TO BE SOLVED: To obtain a dye having an excellent sticking efficiency and an excellent washing fastness by using a specific mono-azo compound. SOLUTION: A mono-azo compound of formula I is used. In the formula, M is H, an alkali metal or another specific colorless metal forming a salt; D is a group shown in formula II or III; R is H, a 1-4C alkyl or a 1-4C alkoxy; R is H, sulfo or carboxy; R is H or sulfo R is R ; and Y is vinyl or an ethyl whose β position is substituted by an alkali-eliminable substituent, preferably β-sulfatoethyl. This compound can be prepared by coupling a diazonium salt of an aromatic amine of the formula: D-NH2 and a compound of formula IV or reacting compounds of formulas V and VI optionally followed by converting the obtained compound to a compound of formula I in which Y is vinyl by an effect of alkali at pH: 9-11 and 0-15 deg.C. In formula VI, Y is an ethyl whose βposition is substituted by an alkali-eliminable substituent. This dye is a fabric reacting dye for orange-red dying.