Formic Acid → HCID 56656401, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 7-[2-((Z)-3-diethylaminoprop-1-enyl)-4-fluorobenzenesulfonylamino]-4H-furo[2,3-c]chromene-6-carboxylate (Intermediate 4, 1.73 g) and lithium hydroxide monohydrate (1.41 g) in dioxane (27 mL) and water (9 mL) was heated to 100° C. for 16 hours, under an atmosphere of nitrogen. The mixture was cooled to room temperature and diluted with DCM (100 mL) and water (100 mL). This mixture was acidified to pH6 using formic acid and the layers were separated. The aqueous layer was extracted with a further 3×100 mL DCM. The combined organic layers were washed with brine, dried (Na2SO4) and filtered. The filtrate was concentrated in vacuo to give a tan solid. This was purified by chromatography on silica, eluting with a mixture of 2M ammonia solution in methanol and DCM with a gradient of 10-20% to give 7-[2-((E)-3-diethylaminoprop-1-enyl)-4-fluorobenzenesulfonyl-amino]-4H-furo[2,3-c]chromene-6-carboxylic acid (0.133 g), isolated as the minor by-product of the reaction.

Provenance & Evidence