Hydrochloric Acid → 5-Amino-3H-thiazolo[4,5]pyrimidine-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of NaOH (0.6 g, 15 mmol, 3 eq) in water (20 ml) was added 5-amino-3H-thiazolo[4,5-d]pyrimidin-2-thione (0.92 g, 5 mmol, 1.0 eq). The mixture was stirred to dissolve. An aqueous solution of H2O2 (0.68 g, 2.3 ml (30%), 20 mmol, 4 eq) was slowly added dropwise to the above solution, keeping the temperature below 50° C. The reaction was then cooled down to room temperature (about 25° C.). Concentrated HCl (37%, 6 ml) was added to the above solution until the pH is less than 1. The mixture is stirred at room temperature for 30 minutes. Celite (2 g) was added to the suspension and the suspension was filtered and washed with water (10 ml). To the filtrate was added 50% NaOH solution to adjust the pH to 5-5.5, stirred for 30 minutes, filtered, washed with water, and dried at 50° C. under vacuum to give 0.52 g (62%) of 5-amino-3H-thiazolo[4,5-d]pyrimidin-2-one as a pale yellow solid. 1H NMR (400 MHz, d6-DMSO) δ 6.70 (s, 2H, ex. D2O), 8.2 (s, 1H), 12.2 (br s, 1H, ex. D2O); MS (+)-ES [M+H]+ m/z 169.

Provenance & Evidence