3-((2-Ethoxy-3,4-dioxocyclobut-1-en-1-yl)amino)-2-hydroxy-N,N-dimethylbenzamide → 2-hydroxy-N,N-dimethyl-3-(2-{[(R)-(5-methylfuran-2-yl)-(3-methyloxetan-3-yl)methyl]amino}-3,4-dioxocyclobut-1-enylamino)benzamide

Participants

Reaction Conditions

Reaction Steps

471 mg (2.6 mmol, 1.3 eq) of C—(R)-(5-methylfuran-2-yl)-C-(3-methyloxetan-3-yl)methylamine were added to 609 mg (2.0 mmol, 1 eq) of 3-(2-ethoxy-3,4-dioxocyclobut-1-enylamino)-2-hydroxy-N,N-dimethylbenzamide dissolved under hot conditions in 40 ml of methanol. The reaction medium was heated at 50° C. for 17 hours. The methanol was evaporated off and the residue (green oil) was chromatographed on silica gel (column puriFlash IR-50SI-80G, Spot II) eluted with dichloromethane/methanol (97/3). The amorphous solid was taken up with diethyl ether to give a yellow powder which was recrystallized from n-propanol. 519 mg of 2-hydroxy-N,N-dimethyl-3-(2-{[(R)-(5-methylfuran-2-yl)-(3-methyloxetan-3-yl)methyl]amino}-3,4-dioxocyclobut-1-enylamino)benzamide were obtained. Yield=70%.

Provenance & Evidence