Hydrochloric Acid → 5-Benzyl-5-(4-cyanophenyl)-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine hydrochloride

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Reaction Steps

A solution of 0.80 mmoles of lithium diisopropylamide, prepared from 0.12 ml of diisopropylamine and 0.32 ml of 2.5M n-butyllithium in 6 ml of tetrahydrofuran at 0°, is slowly added to a solution of 0.17 g of 5-(4-cyanophenyl)-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine in 2 ml of tetrahydrofuran at -79°. After 0.5 h, 0.1 ml of benzyl bromide is added dropwise. The reaction mixture is stirred for an additional 1 h, quenched with 5 ml of water, made acidic with 1N hydrochloric acid, diluted with 20 ml of ether and the layers are separated. The aqueous phase is adjusted to pH=7, extracted with ethyl acetate (3×15 ml) and the organic extracts are dried over sodium sulfate. Filtration and evaporation produces a foam which is treated with one molar equivalent of ethereal hydrogen chloride to yield 5-benzyl-5-(4-cyanophenyl)-5,6,7,8-tetrahydroimidazo[1,5-a]pyridine hydrochloride, m.p. 249°-251°.

Provenance & Evidence