PURPOSE: To obtain a novel intermediate for synthesis of azo dyes that can give dyed or dye-printed fabrics having general fastness particularly light- fastness and moisture-fatness.

CONSTITUTION: This intermediate is a compound represented by formula I [R, R' are each H, sulfo, OH, a 1-4C alkoxy, a halogen, CN; A is a 1-6C alkylene which may be substituted or may be intercepted with O or NR1 (R1 is H, a 1-4C alkyl), a 1-6C alkylenephenylene which may be substituted in its phenyl moiety; Y is vinyl, CH2-CH2-V (V is an eliminable group to be broken under alkaline condition)], typically 4-amino-N-(2-(2-sulfatoethylsulfonyl)ethyl) phthalimide. This compound is prepared by allowing phthalic anhydride to react with a compound of formula II (V1 is U, OH) to form a compound of formula III, converting the product to a compound of formula IV by oxidation, subjecting the obtained compound to selective nitration and reduction to give a compound of formula V and introducing the group R and/or the group R' into the product during or after the synthesis of the compounds of formula IV-formula V or converting the group V1 to any of the group V.