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. Urea hydrogen peroxide (2.8 g, 30 mmol, 6 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 solution and the solution was filtered and washed with water (10 ml). To the filtrate was added 50% NaOH solution to adjust the pH to 5-5.5. The solution was heated up to 50-60° C. for 30 minutes. The resulting solution was cooled down to room temperature, filtered, and washed with water, dried at 50° C. under vacuum to give 0.56 g (67%) of 5-amino-3H-thiazolo[4,5-d]pyrimidin-2-one as a pale yellow solid. 1H NMR, HPLC and LCMS analyses of this product are identical to the product described from Procedure A in Step 2 of Example 1 above.

Provenance & Evidence