Acetic Acid → methyl (1aRS,7bSR)-5-[N-(methoxycarbonyl)-N-(2-amino-4-fluorobenzenesulfonyl)amino]-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

Participants

Reaction Steps

A mixture of methyl (1aRS,7bSR)-5-[N-(methoxycarbonyl)-N-(4-fluoro-2-nitrobenzene-sulfonyl)amino]-1,1a,2,7b-tetrahydro-cyclopropa[c]chromene-4-carboxylate (Intermediate 111, 0.2 g), zinc (0.54 g) and acetic acid (0.5 g) in ethanol (20 mL) was stirred and heated at reflux for 1 hour. After cooling, the solid was filtered off and the filtrate was evaporated to dryness. The residue was treated with saturated aqueous sodium bicarbonate and extracted with ethyl acetate, dried (Na2SO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and petroleum ether with a gradient of 30-50% to give methyl (1aRS,7bSR)-5-[N-(methoxycarbonyl)-N-(2-amino-4-fluorobenzenesulfonyl)amino]-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (0.15 g) as a white solid.

Provenance & Evidence