反应详情

A solution of N-(3-cyano-4,5-dimethylthiophen-2-ylcarbamothioyl)benzamide (example 1a) (1.90 g, 6.03 mmol) and NaOH (2 N, 8.3 mL) in EtOH (25 mL) was stirred at 100° C. under nitrogen for half an hour. After cooling to room temperature, the clear reaction solution was filtered and the filtrate was carefully neutralized with 10% AcOH with vigorous stirring at 0° C. The resultant precipitate was collected by filtration, washed with warm water and then 20% EtOH in water to give the final product 4-amino-5,6-dimethylthieno[2,3-d]pyrimidine-2(1H)-thione (1.11 g, 87%) as an off-white solid. M.p.: >260° C. 1H NMR (400 MHz, DMSO-d6) δ 2.25 (s, 3H), 2.26 (s, 3H). MS 212 (MH+).

1. filtrationthe clear reaction solution was filtered
2. filtrationThe resultant precipitate was collected by filtration
3. washwashed with warm water