Hydrochloric Acid → 1-Methyl-3-(3-oxocyclohex-1-en-1-yl)azepan-2-one

Participants

Reaction Conditions

Reaction Steps

Diisopropylamine (12.14 g, 17.0 ml) in dry tetrahydrofuran (THF 20 ml) was added dropwise to a stirred cooled (-10° C.) solution of butyl lithium (86 ml of 1.4 molar solution in hexane) under nitrogen. After 10 minutes Gilman test was negative. 1-Methylcaprolactam (14.19 g) in THF (20 ml) was added, also at -10° C. Reaction was stirred for 10 minutes at 0° C. and 3-methoxy-2-cyclohexenone (12.6 g, 0.1 mole) in THF (20 ml) was added. The mixture was allowed to warm to room temperature and stirred at room temperature for 1.5 hours, then cooled to -10° C. and decomposed by addition of 2 N HCl (125 ml) rapidly but not allowing temperature to exceed 0° C. The mixture was stirred at room temperature for 30 minutes. The aqueous layer was separated and extracted with dichloromethane. The combined organic extracts were dried over anhydrous magnesium sulphate and evaporated to an oil which crystallised from toluene-light petroleum (b.p. 60°-80° C.) affording the title compound (18.99 g), m.p. 109°-110° C.

Provenance & Evidence