Diethyl squarate → 3-Ethoxy-4-[2-hydroxy-3-(1-hydroxyethyl)phenylamino]cyclobut-3-ene-1,2-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of 1.16 g (7.6 mmol, 1 eq) of 2-amino-6-(1-hydroxyethyl)phenol and 5.15 g (30.3 mmol, 4 eq) of 3,4-diethoxy-3-cyclobutene-1,2-dione in 50 ml of ethanol was heated at 60° C. for 18 hours. The reaction medium was evaporated and the residue was chromatographed on silica gel (column puriFlash IR-50SI/300G, Spot II) eluted with heptane/ethyl acetate (gradient). 800 mg of 3-ethoxy-4-[2-hydroxy-3-(1-hydroxyethyl)phenylamino]cyclobut-3-ene-1,2-dione were obtained in the form of an orange solid. Yield=38%.

Provenance & Evidence