Sodium borohydride → 2-Cyclopentyl-1,2,3,4-tetrahydroquinoline

Participants

Reaction Steps

To a solution of 2-cyclopentylquinoline (7.95 g, 40.3 mmol) and nickel (II) chloride hexahydrate (1.63 g, 6.85 mmol) in methanol (120 ml) cooled in an ice/methanol bath was added sodium borohydride (6.1 g, 161.2 mmol) portionwise over 1.5 h. The cooling bath was removed and the reaction stirred for a further 30 minutes. The methanol was then removed in vacuo. To the resulting black precipitate was added 2 M hydrochloric acid (100 ml) and then basified with 10 M potassium hydroxide. The mixture was poured into a separating funnel and extracted with ether (4×200 ml). The combined organic layers were dried (MgSO4), filtered and the solvent removed in vacuo to give 2-cyclopentyl-1,2,3,4-tetrahydroquinoline (7.45 g, 37.1 mmol) as a light brown oil.

Provenance & Evidence