Water → 6-Bromo-1,4,4-trimethyl-3,4-dihydroquinolin-2(1H)-one

Participants

Reaction Steps

N-(4-bromophenyl)-N-methyl-3-methyl-2-butenamide (Intermediate 54, 6.42 g, 24 mmol) was heated to 130° C. and aluminum chloride (5 g, 37.4 mmol) was added in portions over 0.5 h. The reaction mixture was stirred for 1 hour at the same temperature and then cooled to room temperature. Ice was added cautiously to the solid, followed by 200 mL of iced water. The reaction mixture was then extracted with ether (×2) and dichloromethane (×1) and the combined organic phase was dried over anhydrous magnesium sulfate and evaporated in vacuo to yield a brown solid. The solid was treated with hexane-dichloromethane and filtered to afford 1.7g of product. The mother liquor was evaporated and purified by flash column chromatography on silica gel (230-400 mesh) to afford 2.9g of the title compound as a solid (total 72%).

Provenance & Evidence