Diethyl 4-(4-chloro-2-aminobenzoyl)-1H-pyrazole-3,5-dicarboxylate → 7-Chloro-3-(ethoxycarbonyl)pyrazolo[3,4-c][1]benzazepine-4,10-(1H,9H)dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-hydroxypyridine (1.30 g, 13.69 mmol) in toluene (400 mL) was added diethyl 4-(4-chloro-2-amino-benzoyl)-1H-pyrazole-3,5-dicarboxylate (5 g, 13.69 mmol). The mixture was refluxed for 2 days and then the solvent was distilled off and the residual solid was heated at 171-172° C. for 4 days. The solid was allowed to cool and was continuously chromatographed eluting for 2 hours with dichloromethane to remove starting material. The remaining material on the column was eluted with chloroform:2-propanol (97:3) for 4 days. After each day the solvent in the receiving flask was replaced with fresh solvent. Filtering the solvent from the first two receiving flasks gave the title compound as a white solid (1.65 g, 38%, mp 290° C.). Alternatively, the title compound can preferably be removed from the column by elution with ethanol/chloroform (7:93).

Provenance & Evidence