Cyclopropyl phenyl ketone → Cyclopropyl(phenyl)methanamine

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Reaction Steps

100 g of cyclopropyl phenyl ketone are stirred in 2,000 ml of methanol with 500 g of pre-dried ammonium acetate and 50 g of sodium cyanoborohydride, in the presence of 4 A molecular sieves, under argon for 4 days at 50° C. After cooling, the molecular sieves are filtered off and hydrochloric acid is added to bring the pH to 2. The methanol is evaporated to dryness under vacuum and the residue is taken up in diethyl ether. The aqueous phase is washed with ethyl ether and basified by addition of concentrated potassium hydroxide solution so that the pH is above 10. The mixture is extracted twice with methylene chloride and the extracts are washed with saturated sodium chloride solution, dried over anhydrous magnesium sulphate and then concentrated under vacuum to give α-cyclopropylbenzylamine.

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