Dimethyl Sulfoxide → N-(5,8-dimethoxy-[1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-2-fluoro-6-(trifluoromethyl)benzenesulfonamide

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Reaction Steps

2-Amino-5,8-dimethoxy(1,2,4)triazolo[1,5-c]pyrimidine (1.0 g, 5.1 mmol) was suspended in 15 mL of dry acetonitrile in a round bottom flask equipped with magnetic stirring. To this suspension was added crude 2-fluoro-6-trifluoromethylbenzenesulfonyl chloride (3.16 g, 10.2 mmol), dry pyridine (0.8 g, 10.2 mmol), dry dimethylsulfoxide (DMSO, 0.1 g, 1.3 mmol), and the flask was fitted with a CaSO4 drying tube. The reaction was monitored by HPLC analysis over a 9 day period, during which time an additional 4 equivalents of pyridine and 0.1 equivalents of DMSO were added. The dark solution was diluted with methylene chloride (300 mL), washed with 2N hydrochloric acid (2×200 mL), washed with water (2×200 mL), dried (MgSO4), filtered, and the solvent evaporated in vacuo to give a brown residue. The brown residue was triturated 5 with diethyl ether to afford the product as a tan solid: (1.0 g, 46% yield), mp 201-203° C.; Anal. Calcd for C14H11F4N5O4S: C 39.91, H 2.63, N 16.62, S 7.61; found: C 39.77, H 2.46, N 16.34, S 7.64. 1H NMR (DMSO-d6): δ8 3.85 (s, 3H), 4.05 (s, 3H), 7.58 (s, 1H), 7.73 (m, 1H), 7.88 (s, 2H), 12.85 (bs, 1H).

Provenance & Evidence