Dimethyl Sulfoxide → 3-Methoxy-N-(5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidin-2-yl)thiophene-2-sulfonamide

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Reaction Steps

To a slurry of 0.8 g (4.5 mmol) of 2-amino-5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidine in 7 mL of acetonitrile was added 1.3 g (6.1 mmol) of 3-methoxythiophene-2-sulfonylchloride, 0.6 mL of dry pyridine and 0.003 mL of dry DMSO. After 96 hr, the reaction mixture was partitioned with CH2Cl2 and water. The organic phase was separated, washed with dilute aqueous HCl, dried over MgSO4, filtered and concentrated. The residue was taken into a small amount of CH2Cl2 before ether was added slowly with stirring to precipitate a fine tan solid. The solid was collected by filtration and dried under vacuum to give 0.85 g (50%) of the desired product. mp 227-228° C. 1H NMR (300 MHz, DMSO-d6): δ 12.1 (s, 1H); 7.8 (d, 1H, J=5.6); 7.6 (s, 1H); 7.0 (d, 1H, J=5.6); 4.1 (s, 3H); 3.9 (s, 3H); 3.8 (s, 3H). Calc'd for C12H13N5O5S2: C, 38.81; H, 3.53; N, 18.86; S, 17.27. Found: C, 38.32; H, 3.49; N, 18.91; S, 17.34.

Provenance & Evidence