N Methyl 4 nitrophthalimide ( 4 NPI) was reduced by metal such as iron powder in dilute acidic solution and then hydrolyzed in solution of sodium hydroxide to provide di sodium 4 aminophthalate.

• 将 4 硝基邻苯二甲酰亚甲胺 (4 NPI)用铁粉还原为 4 氨基邻苯二甲酰亚甲胺 ；再在氢氧化钠水溶液中水解成 4 氨基邻苯二甲酸钠 .