Pyrrolidine → Sunitinib acid

Participants

Reaction Steps

A mixture of 5-fluoro-1,3-dihydroindol-2-one (A2) (20 g, 132 mmol), 5-formyl-2,4-dimethylpyrrole-3-carboxylic acid (A1) (21.1 g, 126 mmol), pyrrolidine (5 ml) and absolute ethanol (400 mL) were heated to reflux for 3 hours. Then the mixture was cooled to room temperature and the solid was collected by filtration, washed with ethanol (100 mL). The solid was stirred in ethanol (350 ml) at reflux for 0.5 h again. The mixture was cooled to room temperature and the solid was collected by filtration, washed with ethanol (100 mL) and dried under vacuum overnight to give (Z)-5-((5-fluoro-2-oxoindolin-3-ylidene)methyl)-2,4-dimethyl-1H-pyrrole-3-carboxylic acid (A3) (35.3 g, 93%) as orange solid. LC-MS observed [M−H]+: 299.2.

Provenance & Evidence