Diethyl squarate → 6-Chloro-3-(2-ethoxy-3,4-dioxo-cyclobut-1-enylamino)-2-hydroxy-N-methoxy-N-ethyl-benzenesulfonamide

Participants

Reaction Conditions

Reaction Steps

A solution of 3,4-diethoxy-3-cyclobutene-1,2-dione (0.30 g, 1.76 mmol) in ethanol (5 ml) was treated with TEA (250 μl, 1.80 mmol) and the reaction mixture was heated to 45° C. A solution of 3-amino-6-chloro-2-hydroxy-N-methoxy-N-ethyl-benzenesulfonamide (0.58 g, 2.07 mmol) in EtOH (5 ml) was added dropwise to the reaction mixture. The reaction mixture was stirred at 45° C. for 1 hour and then concentrated in vacuo. The residue was purified using flash chromatography (50% EtOAc in iso-hexane) to furnish a solid [M+H]+ 405.2.

Provenance & Evidence