Formic Acid → HCID 71471050, compound

Participants

Reaction Steps

Lithium hydroxide (0.048 g) was added to a solution of methyl cis-(3aRS,9bRS)-7-(benzenesulfonylamino)-1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-6-carboxylate (Intermediate 1, 0.08 g) in a mixture of dioxane (10 mL) and water (5 mL) and the resultant mixture was irradiated in the microwave at 110° C. with air cooling for 20 minutes. Further lithium hydroxide (0.2 g) was added and the mixture was irradiated in the microwave at 110° C. with air cooling for a total of 80 minutes. After cooling, the solution was acidified by addition of aqueous formic acid solution (10%) and the resultant mixture was extracted with ethyl acetate, dried (MgSO4) and filtered. The filtrate was evaporated to dryness. The residue was dissolved in a mixture of methanol (10 mL) and water (5 mL) and treated with lithium hydroxide (0.2 g) then irradiated in the microwave at 110° C. with air cooling for 40 minutes. After cooling, the solution was acidified by addition of formic acid (10%) and the resultant mixture was extracted with ethyl acetate, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by preparative HPLC (C18) eluting with a mixture of acetonitrile and water, containing 0.1% formic acid, with a gradient of 30-50% to give cis-(3aRS,9bRS)-7-(benzenesulfonylamino)-1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-6-carboxylic acid (0.019 g) as a white solid.

Provenance & Evidence