3-Cyclobutene-1,2-dione, 3,4-dimethoxy- → HCID 89534509, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl (S)-1-(3-amino-2,6-difluorobenzoyl)pyrrolidine-2-carboxylate (prepared above) and 4.20 g (29.55 mmol) of 3,4-dimethoxycyclobut-3-ene-1,2-dione in solution in 50 ml of methanol was heated at 60° C. for one hour and then stirred at ambient temperature for 4 hours. The reaction medium was concentrated and the residue (6.29 g) was chromatographed on silica gel (300 g prepacked column, eluted with heptane/ethyl acetate, from 70% to 100% of ethyl acetate). 2.30 g of methyl (S)-1-[2,6-difluoro-3-(2-methoxy-3,4-dioxocyclobut-1-enylamino)benzoyl]-pyrrolidine-2-carboxylate were obtained. Yield=79%.

Provenance & Evidence