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

Participants

Reaction Steps

4-Chlorobutyryl chloride (3.0 g) was added to a stirred, cooled solution of methyl (1aRS,7bSR)-5-[N-(methoxycarbonyl)-N-(2-amino-4-fluorobenzenesulfonyl]amino}-1,1a,2,7b-tetrahydrocyclopropa-[c]chromene-4-carboxylate (Intermediate 110, 0.135 g) and triethylamine (1.0 g) in THF (10 mL) at 0° C. On completion of the addition, the mixture was stirred at room temperature for 4 hours. Saturated aqueous sodium bicarbonate was added and the mixture was 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 20-25% to give methyl (1aRS,7bSR)-5-{N-[methoxycarbonyl]-N-[2-(4-chlorobutyrylamino)-4-fluoro-benzenesulfonyl]amino}-1,1a,2,7b-tetrahydrocyclopropa-[c]chromene-4-carboxylate (0.15 g) as a yellow oil.

Provenance & Evidence