Hydrochloric Acid → 8-Cyano-3-methyl-5,6,7,8-tetrahydroquinoline

Participants

Reaction Steps

A solution of 3-methyl-5,6,7,8-tetrahydroquinoline (29 g., 0.2 mol) in benzene (200 ml.) was cooled to 0° C and treated dropwise with a 15% w/w solution of n-butyl lithium in hexane (88 ml., 0.2 mol) under nitrogen. After 1 hour at 0° C the reaction mixture was added portionwise to a solution of trimethylsilylisothiocyanate (112 ml., 0.8 mol.) in benzene (200 ml.) at 0° C and under nitrogen. After 21/2 hours at room temperature the reaction mixture was treated with water (100 ml.) and with 2N HCl to pH 2.0. The aqueous layer was separated, washed with ethyl acetate (1 × 50 ml.) and the pH adjusted to 9.0 with sodium carbonate and extracted with chloroform (3 × 100 ml.) The combined chloroform extracts were dried (MgSO4) and the solvent removed in vacuo to give a red oil which was distilled first at 0.25 mmHg to give recovered 3-methyl-5,6,7,8-tetrahydroquinoline (17 g., 59%) b.p. 54°-7° and then at 0.05 mmHg to give the title compound as a pale red oil (12 g. 35%) b.p. 115°-20° RT = 4.1/4 min. (3% SE30, 200° C) identical to authentic material.

Provenance & Evidence