Hydrochloric Acid → 6-Bromo-1-methyl-1,2,3,4-tetrahydroquinolin-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-bromo-3,4-dihydroquinolin-2(1H)-one (5 g, 22.1 mmol) in DMF (100 mL) cooled to 0° C. was added potassium tert-butoxide (4.96 g, 44.2 mmol) portionwise and the reaction mixture was stirred at 0° C. for 15 min. Then, methyl iodide (4.08 g, 28.8 mmol) was added and the reaction mixture allowed to warm up to room temperature and stirring was continued over night. More MeI (1.25 g, 8.86 mmol) was added and the reaction mixture was heated to 40° C. until completion of the reaction. The mixture was diluted with EtOAc, poured into 100 mL of 1M HCl and the aqueous phase was extracted with EtOAc (2×200 mL). Combined organics were washed with brine, dried over Na2SO4, filtered and evaporated to dryness. The residue was purified by silica gel flash chromatography eluting with a 0 to 30% EtOAc-heptane gradient to give the title compound (4.23 g, 80%) as an off white solid. MS: 240.0, 242.1 (M+H+).

Provenance & Evidence