Acetonitrile → 6-bromo-7-(1-bromoethyl)-3-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one

Participants

Reaction Steps

Under nitrogen, a suspension of 7-(1-bromoethyl)-3-methyl-5H-[1,3]thiazolo[3,2-a]pyrimidin-5-one (13.2 g, 48.3 mmol) in acetonitrile (100 mL, 2000 mmol) was stirred until a clear solution was obtained. N-Bromosuccinimide (9.891 g, 55.57 mmol) was then added and the reaction mixture was stirred at 50° C. After 20 min, HPLC indicated that the reaction was complete. A solution of sodium sulfite (3.046 g, 24.16 mmol) in water (50 mL) was added and the mixture was stirred at room temperature for 20 min. Water (200 mL) was added slowly and the mixture stirred at room temperature for 30 min. and then filtered. The solid was washed with water (100 mL×3) and dried to give 6-bromo-7-(1-bromoethyl)-3-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one as an off-white solid (15.61 g, 91%). LCMS calculated for C9H9Br2N2OS (M+H)+: m/z 352.87, 354.87. Found: 352.65, 354.60. 1H NMR (400 MHz, DMSO-d6) δ 7.15 (q, J=1.3 Hz, 1H), 5.51 (q, J=6.7 Hz, 1H), 2.66 (d, J=1.2 Hz, 3H), 1.90 (d, J=6.7 Hz, 3H).

Provenance & Evidence