Ammonia → 3-(4-(1H-Pyrazol-1-yl)benzyl)-6-bromo-2,4-dichloro-8-methylquinoline

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(4-(1H-pyrazol-1-yl)benzyl)malonic acid (20.0 g, 71.5 mmol, Intermediate 6, step b) and 4-bromo-2-methylaniline (13.3 g, 71.5 mmol) in phosphorus oxychloride (66.8 mL, 712 mmol) was heated at 105° C. After 5 hours, the mixture was cooled to room temperature and added to water (600 mL) with cooling so that the internal temperature did not exceed 35° C. The pH of the mixture was adjusted to 8-9 by the slow addition of saturated aqueous ammonia solution such that the internal temperature did not exceed 35° C. After 30 minutes of stirring at room temperature, the mixture was filtered and the solid material was suspended in acetonitrile (200 mL), sonicated and filtered. The solid material was collected and suspended in DCM (80 mL), sonicated and filtered and washed with ether (40 mL). The filtrate was concentrated, suspended in DCM (40 mL), sonicated and filtered to provide more of the desired product. To 5 g of the isolated solid, DCM (300 mL) and aqueous saturated NaHCO3 (100 mL) were added and the mixture was transferred to a separatory funnel, and the layers were separated. The DCM layer was further washed with brine (100 mL), dried (MgSO4), filtered and the solvents were removed under reduced pressure. The crude material was purified using flash-column chromatography on silica gel eluting with DCM to provide 3-(4-(1H-pyrazol-1-yl)benzyl)-6-bromo-2,4-dichloro-8-methylquinoline as an off-white solid.

Provenance & Evidence