Hydrochloric Acid → 5,7-dimethyl-N-(2,6-difluorophenyl)pyrazolo[1,5-a]pyrimidine-2-sulfonamide

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Reaction Conditions

Reaction Steps

A slurry of 4.8 g (10.8 mmole) of 3-carboethoxy-5,7-dimethyl-N-(2,6-difluorophenyl)pyrazolo[1,5-a]pyrimidine-2-sulfonamide in 30 ml glacial HOAc was stirred at room temperature with 1 ml concentrated HCl and 3 ml water for 2 hours. The mixture was then heated at 110° C. for 16 hours. A further 1 ml concentrated HCl and 5 ml water were added and the mixture stirred for 16 hours, then cooled to room temperature. The mixture was thrown onto ice and the resultant solid collected by filtration, washed with water and dried to give 2.34 g (64 percent) of the product as a brown powder, m.p. 201°-208° C. An analytical sample was recrystallized from CH3CN/EtOAc/CH3OH, m.p. 209°-211° C. (dec). 1H NMR (DMSO-d-6): 10.3 (s, 1H, NH), 7.37 (m, 1H, benzene), 7.10 (m including s, 3H, aromatic and H-3 or H-6), 6.82 (s, 1H, H-3 or H-6), 2.63 (s, 3H, CH3), 2.53 (s, 3H, CH3). IR (KBr): 3400, 3050, 2800, 1625, 1600, 1540, 1480, 1430, 1325, 1290, 1240, 1170, 1140, 1000. Analysis: Calculated for C14H12N4F2O2S: C, 49.70; H, 3.58; N, 16.56. Found: C, 48.68; H, 3.74, N, 15.98.

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