16298-03-6

6761-52-0

The general procedure for the synthesis of 3-aminopyrazine-2-carboxylic acid methyl ester from 3-aminopyrazine-2-carboxylic acid was as follows: hydrazine monohydrate (34 mL, 1094.95 mmol) was added batchwise to a stirred ethanol (65 mL) suspension of 3-aminopyrazine-2-carboxylic acid methyl ester (21.3 g, 139.09 mmol) at room temperature. The resulting mixture was stirred continuously at 60 °C for 2 h, followed by cooling to room temperature and filtration. The solid product was washed with cold ethanol (2 x 25 mL) and after drying to constant weight, 3-aminopyrazine-2-carbohydrazide (20.75 g, 97% yield) was obtained as a beige solid. The product was characterized by 1H NMR (DMSO-d6): δ 4.49 (2H, d), 7.46 (2H, br s), 7.78 (1H, d), 8.17 (1H, d), 9.79 (1H, t); mass spectrometry analysis showed [M + H]+ m/z = 154.