Tri-tert-butylphosphine tetrafluoroborate → Methyl 7-[2-((Z)-3-diethylaminoprop-1-enyl)-4-fluorobenzenesulfonylamino]-4H-furo[2,3-c]chromene-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 7-(2-bromo-4-fluorobenzenesulfonylamino)-4H-furo[2,3-c]chromene-6-carboxylate (Intermediate 10, 2.04 g), N,N-diethyl-N—((Z)-1-tributylstannanylprop-1-en-3-yl)amine (Intermediate 11, 3.4 g), tri-tert-butylphosphonium tetrafluoroborate (0.246 g), tris-(dibenzylideneacetone)dipalladium (0.0.388 g) in dioxane (35 mL) was degassed and purged with argon then heated at 100° C. for 3.5 hours. After cooling, the mixture was diluted with ethyl acetate and filtered. The filtrate was washed with water, dried (Na2SO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of ammonia in methanol (2M) and DCM with a gradient of 0-10%. The product was triturated with ether and the solid was collected by filtration to give methyl 7-[2-((Z)-3-diethylaminoprop-1-en-1-yl)-4-fluorobenzenesulfonyl-amino]-4H-furo[2,3-c]chromene-6-carboxylate (1.47 g) as a pale orange solid.

Provenance & Evidence