| 摘要 |
PROBLEM TO BE SOLVED: To provide the subject new compound useful as a color-developing agent, a charge regulation agent, or the like, for heat-sensitive recording material. SOLUTION: This compound is expressed by formula I (R1 and R2 are each H, an alkyl, an aryl or a halogen), e.g. the compound of formula II. The compound of formula I can be produced by reacting phthalic anhydride (or its nucleus-substituted substance) with p-phenylsulfonyl hydrazide (or its nucleus- substituted substance) in a polar organic solvent such as acetonitrile at room temperature or under heating for several hours, leaving the produced reaction product at room temperature or under cooling to effect the crystal precipitation and subjecting the crystal to filtration and purification. The compound has carboxyl group and is usable as a color developing agent for heat-sensitive recording material together with leuco dye and other additives and also usable as a charge regulation agent, intermediate for Pharmaceuticals, or the like. |
