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

Temperature

25 °C

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.

1. dissolutionto dissolve
2. customthe temperature below 50° C
3. stirringThe mixture is stirred at room temperature for 30 minutes
4. additionCelite (2 g) was added to the solution
5. filtrationthe solution was filtered
6. washwashed with water (10 ml)
7. additionTo the filtrate was added 50% NaOH solution
8. temperatureThe solution was heated up to 50-60° C. for 30 minutes
9. temperatureThe resulting solution was cooled down to room temperature
10. filtrationfiltered
11. washwashed with water
12. customdried at 50° C. under vacuum

ORD record

ord-6dffb2525dea4ebea8fa558bc0e2b5ac

Source dataset

uspto-grants-2010_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07781581B2