2-氨基-4-甲氧基氯代苯甲酸的合成研究

Synthesis of chlorine substituted 2-amino-4-methoxybenzoic acid

以2-氨基-4-甲氧基苯甲酸甲酯为原料,通过氯代反应,再分别通过酯水解反应得到化合物2-氨基-5-氯-4-甲氧基苯甲酸和2-氨基-3-氯-4-甲氧基苯甲酸。其中间体及产物结构经1H NMR、13C NMR和ESI-MS确证,并考察了最佳氯代反应条件。结果表明:物料配比为n(2-氨基-4-甲氧基苯甲酸甲酯)∶n(NCS)=1∶1. 2,反应溶剂为N,N-二甲基甲酰胺,反应时间为16 h,两种氯代产物2-氨基-5-氯-4-甲氧基苯甲酸甲酯和2-氨基-3-氯-4-甲氧基苯甲酸甲酯收率分别为47%和39%。

2-Amino-5-chloro-4-methoxybenzoic acid and 2-amino-3-chloro-4-methoxybenzoic acid were synthesized from methyl 3-hydroxy-4-iodobenzoate through a-two step reaction,involving chlorination reaction and hydrolysis reaction of ester.The structures of intermediates and the products were confirmed by1 H NMR,13 C NMR and ESI-MS.The optimal reaction conditions of chlorination reaction were also investigated.The results showed that methyl 2-amino-5-chloro-4-methoxybenzoate and methyl 2-amino-3-chloro-4-methoxybenzoate were obtained in 47%and 39%yield respectively by the mole ratio of n( NCS)∶ n( methyl 3-hydroxy-4-iodobenzoate)= 1 ∶ 1. 2,reaction was stirred in DMF at 25 ℃ for 16 h.