Sodium Hydroxide → HCID 178435039, compound

Participants

Reaction Steps

A solution of N-(3-cyano-4,5-dimethylthiophen-2-ylcarbamoyl)benzamide (example 4a) (44.35 g, 148.1 mmol) and NaOH (2 N, 204 mL) in EtOH (400 mL) was stirred at 100° C. under nitrogen for four hours. The clear reaction solution was filtered and the filtrate was cooling to room temperature, and then was carefully neutralized with 10% AcOH (˜120 mL) with vigorous stirring at 0° C. After stirring overnight from 0° C. to room temperature, the resultant precipitate was collected by filtration, washed with warm water (60-70° C., 150 mL×4) and 20% EtOH in water (200 mL×2), and then dried at 50° C. under vacuum overnight to give the final product 4-amino-5,6-dimethylthieno[2,3-d]pyrimidin-2(1H)-one (27.7 g, 96%) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 7.98 (brs, 1H), 2.24 (s, 3H), 2.19 (s, 3H). MS 196 (MH+).

Provenance & Evidence