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 1.7 g of product. The mother liquor was evaporated and purified by flash column chromatography on silica gel (230-400 mesh) to afford 2.9 g of the title compound as a solid (total 72%).

Provenance & Evidence