Methyl 5-amino-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate → methyl (1aRS,7bSR)-5-[4-fluoro-2-(methoxycarbonylmethyl)-benzenesulfonylamino]-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

Participants

Reaction Steps

A solution of methyl (2-chlorosulfonyl-5-fluorophenyl)acetate (Intermediate 85, 0.293 g) and methyl (1aRS,7bSR)-5-amino-1,1a,2,7b-tetrahydro-cyclopropa[c]chromene-4-carboxylate (Intermediate 42, 0.219 g) in pyridine (1 mL) and DCM (3 mL) was left to stand at room temperature for 4 days. The mixture was diluted with DCM, washed with 2M hydrochloric acid and filtered through a phase separator. 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 0-40% to give methyl (1aRS,7bSR)-5-[4-fluoro-2-(methoxycarbonylmethyl)-benzenesulfonylamino]-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (0.438 g) as a colourless gum.

Provenance & Evidence