2-Aminothiazole-5-carboxylic acid

32955-21-8

40283-46-3

General procedure for the synthesis of 2-aminothiazole-5-carboxylic acid from ethyl 2-aminothiazole-5-carboxylate: sodium hydroxide (0.65 g, 16.3 mmol) was added to a mixed THF/water (2:1, v/v) solution containing ethyl 2-aminothiazole-5-carboxylate (0.80 g, 4.32 mmol) and the reaction mixture was heated to reflux overnight. Upon completion of the reaction, THF was removed by distillation under reduced pressure.Subsequently, the reaction mixture was neutralized with 1 M hydrochloric acid solution. The resulting precipitate was collected by filtration, washed with ether and dried at 60 °C overnight. An off-white crystalline product was obtained in 86% yield with a melting point of 168-171 °C (literature value: 172-173 °C). The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ 7.81 (s, 1H, thiazole-H), 8.99 (br s, 2H, NH2) ppm. high-resolution mass spectrometry (HRMS-ESI) analysis: m/z [M+H]+ calculated value of 145.1475 (C4H5N2O2S), measured value 145.1502.