反应详情

A mixture of ethyl 2-amino-4-methylthiazole-5-carboxylate (6.58 g, 35.5 mmol) and NaOH (5.40 g, 135 mmol) in tetrahydrofuran (60 mL) and water (30 mL) was heated to reflux overnight. Tetrahydrofuran was removed in vacuo, and the residue was neutralized with 5% hydrochloric acid solution to pH 5˜6. The precipitate obtained was collected by filtration and dried to afford the crude 2-amino-4-methylthiazole-5-carboxylic acid (5.20 g, 94%): 1H NMR (300 MHz, DMSO-d6) δ 7.63 (s, 2H), 2.30 (s, 3H); MS (ES+) m/z 159.1 (M+1).

1. temperaturewas heated
2. temperatureto reflux overnight
3. customTetrahydrofuran was removed in vacuo
4. customThe precipitate obtained
5. filtrationwas collected by filtration
6. customdried