| 摘要 |
PURPOSE:To readily obtain the subject compound useful as an intermediate for heat-sensitive coloring matters, etc., in high yield and purity, by treating a specific isoindolinone compound with an oxidizing agent in the presence of an alkali. CONSTITUTION:An isoindolinone compound expressed by formula I (R1, R2, R5 and R6 are H, alkyl, alkoxyalkyl, haloalkyl, allyl, etc.; R3 is H, halogen or alkyl; R4 is H, alkyl, phenyl or acyl) is treated with an oxidizing agent, such as hypohalite or hydrogen peroxide, in the presence of an alkali, such as NaOH or KOH, to afford a benzoic acid derivative expressed by formula II. The reaction is carried out at 40-200 deg.C, preferably 80-150 deg.C temperature. A heat- or pressure-sensitive dye can be obtained by the above-mentioned method without normally requiring operation, such as purification. |
