Pyridine → HCID 66685312, compound

Participants

Reaction Steps

To a stirred solution of methyl 7-amino-4H-chromeno[3,4-d]isothiazole-6-carboxylate (Intermediate 74, 0.300 g) in DCM (15 mL) was added pyridine (2.5 mL), followed by 2-bromo-4-fluorobenzenesulfonyl chloride (0.468 g). The resultant mixture was stirred at room temperature overnight. A further amount of 2-bromo-4-fluorobenzenesulfonyl chloride (0.300 g) was added and stirring was continued overnight. The mixture was diluted with DCM and washed with 0.5M hydrochloric acid and aqueous sodium bicarbonate. The organic layer was dried (Na2SO4), filtered and the filtrate was concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane, with a gradient of 15-45% to give methyl 7-(2-bromo-4-fluorobenzenesulfonylamino)-4H-chromeno[3,4-d]isothiazole-6-carboxylate (0.460 g) as a cream solid.

Provenance & Evidence