Pyridine → methyl (1aRS,7bSR)-5-(2-bromo-4-fluorobenzenesulfonylamino)-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

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Reaction Steps

Methyl (1aRS,7bSR)-5-amino-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (Intermediate 42, 0.120 g) was suspended in DCM (5 mL). Pyridine (0.885 mL) and 2-bromo-4-fluorobenzenesulfonyl chloride (0.180 g) were added. The mixture was stirred at room temperature for 5 hours then concentrated in vacuo. The residue was dissolved in ethyl acetate and washed with 0.5M aqueous hydrochloric acid solution, dried (MgSO4) and filtered. The filtrate was concentrated in vacuo and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane, with a gradient of 5-10% to give methyl (1aRS,7bSR)-5-(2-bromo-4-fluorobenzenesulfonylamino)-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (0.208 g) as a colourless oil.

Provenance & Evidence