Formic Acid → cis-(3aRS,9bRS)-7-[2-(3-{pyrrolidin-1-yl}propyl)-4-fluorobenzenesulfonylamino]-1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

Lithium hydroxide (0.028 g) was added to a solution of methyl cis-(3aRS,9bRS)-7-[2-(3-{pyrrolidin-1-yl}propyl)-4-fluorobenzenesulfonylamino]-1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-6-carboxylate (Intermediate 14, 0.06 g) in dioxane (2 mL) and water (1 mL) and the mixture was stirred and heated at 80° C. for 8 hours. After cooling, the mixture was acidified by addition of aqueous formic acid solution (10%) and extracted with DCM. The organic layer was dried (MgSO4) 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 1-10%. The isolated solid was triturated with a mixture of ether and cyclohexane (50%) and the solid was collected by filtration. The solid was purified by preparative HPLC (C18) eluting with a mixture of acetonitrile and water, containing 0.1% formic acid, with a gradient of 10-95%. The isolated product was triturated with ether and the solid was collected by filtration to give cis-(3aRS,9bRS)-7-[2-(3-{pyrrolidin-1-yl}propyl)-4-fluorobenzenesulfonylamino]-1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-6-carboxylic acid (0.006 g) as a white solid.

Provenance & Evidence