Sodium Hydroxide → 1-(3,4-Dihydro-2H-chromen-3-yl)methanamine hydrochloride

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Reaction Steps

First 1.77 g (13.32 mmol) of aluminium chloride in 50 ml of absolute diethyl ether are added dropwise while stirring at room temperature to a suspension of 3.04 g (80 mmol) of lithium aluminium hydride in 100 ml of absolute diethyl ether. Then 6.29 g (40 mmol) of 3-cyanochromene [R. C. Gupta et al., Ind. J. Chem. 21B, 344 (1982)] in 50 ml of absolute tetrahydrofuran are added dropwise within a period of 20 minutes. The reaction mixture is boiled under reflux for 16 hours. After it has cooled, it is carefully decomposed with 3.1 ml of water, 3.1 ml of sodium hydroxide solution (15% strength) and 9.3 ml of water. The precipitate formed is filtered off with suction, the filtrate is concentrated by evaporation in vacuo and the oily residue is dissolved in diethyl ether. The organic phase is washed with water and extracted with 2N hydrochloric acid. The combined hydrochloric acid extracts are rendered alkaline, while cold, with sodium hydroxide solution (30% strength) and extracted by shaking with dichloromethane. After drying the combined organic phases over sodium sulphate and concentrating in vacuo, 3.5 g (53.6%) of 3-aminomethylchroman are obtained in the form of a yellow oil. The 3-aminomethylchroman hydrochloride produced therefrom using hydrochloric acid in diethyl ether is recrystallised from methanol/diethyl ether and melts at 218°-219°.

Provenance & Evidence