Water → HCID 178524332, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-(4-cyanobenzyl)-5-phenyl-1H-pyrazolo[4,3-c][1,8]naphthyridin-4 (5H)-one (180 mg, 0.48 mmol, prepared in Example 31) in DMSO (18 ml) was added 50% sulfuric acid (10 ml), and the mixture was stirred at 140° C. After water (5 ml) was added, the mixture was heated under reflux, admixed with additional water (5 ml), and heated under reflux for totally 3 hours. The reaction mixture was admixed with water, and filtered to give precipitates which were dried to afford 3-(4-carboxybenzyl)-5-phenyl-1H-pyrazolo[4,3-c][1,8]naphthyridin-4 (5H)-one (106 mg, 56%).

Provenance & Evidence