Water → 4-Chlorothieno[3,2-d]pyrimidine

Participants

Reaction Steps

Dimethyl formamide (6.6 mL, 85.4 mmol) in 50 mL of dichloroethane was cooled to 0° C. and oxalyl chloride (62 mL, 124 mmol, 2M in dichloromethane) was added slowly over several minutes forming a white gel. 3H-thieno[3,2-d]pyrimidin-4-one (5.90 g, 38.8 mmol) was added and the reaction mixture was heated to reflux. After 2.5 hours the mixture was cooled to room temperature and poured into water. The product was extracted into dichloromethane (3×100 mL), dried over sodium sulfate, and concentrated in vacuo to afford 5.01 g (76%) of 4-chloro-thieno[3,2-d]pyrimidine. 1H NMR (400 MHz, DMSO) d 8.99 (s, 1H), 8.55 (d, 1H), 7.71 (d, 1H). LC-MS: 171 (MH+); HPLC RT: 2.85 minutes.

Provenance & Evidence