Sodium Pyrosulfite → HCID 178458740, compound

Participants

Reaction Steps

To a stirred solution of 0.2 g (0.59 mmol) of 3-isopropoxy-5-oxo-6,7-dihydro-4H-thieno[3,2-c]thiopyran-2-carboxylic acid (1H-tetrazol-5-yl)amide (from Example 5) in 15 mL of glacial acetic acid was added in one portion 0.19 g of 31.5% aqueous hydrogen peroxide. The reaction mixture stood at 24° C. for 3 days, and then was treated with 10% aqueous sodium metabisulfite. The solvent was removed by evaporation under reduced pressure to give a solid residue. The solid was crystallized from 20 mL of ethylacetate and 1 mL of water to provide 0.115 g of 3-isopropoxy-5,5-dioxo-6,7-dihydro-4H-thieno[3,2-c]thiopyran-2-carboxylic acid (1H-tetrazol-5-yl) amide, mp 230°-232° C.

Provenance & Evidence