An efficient and scalable synthesis of 7-amino-3-methylisobenzofuran-1(3H)-one (1) and 2-amino-6-ethylbenzoic acid (2) has been developed via a one-step catalytic hydrogenation. The triethylammonium salt of 2-acetyl-6-nitrobenzoic acid was used as the starting material and 1 was prepared in a biphasic solvent system of toluene/H₂O, while 2 was obtained when the solvent was replaced with H₂O. Intermediates 1 and 2 could be used to synthesize Pyriftalid and Paquinimod, respectively.

中文翻译：

---

氢化法简便合成丙酮酸和帕喹莫德的关键中间体

通过一步催化加氢，已开发出有效且可扩展的7-氨基-3-甲基异苯并呋喃-1（3 H）-一（1）和2-氨基-6-乙基苯甲酸（2）的合成方法。的2-乙酰基-6-硝基苯甲酸三乙基铵盐作为起始原料和1在甲苯中的两相溶剂体系制备/ H ₂ O，而2时用H置换溶剂，得到₂ O.中间体1和2可以分别用于合成Pyriftalid和Paquinimod。