Cyclopropyl phenyl ketone → cyclopropyl(phenyl)methanamine

Participants

Reaction Steps

Stir 100 g of cyclopropyl phenyl ketone in 2000 ml of methanol with 500 g of previously dried ammonium acetate and 50 g of sodium cyanoborohydride at 50° C. for 4 days under argon in the presence of 4 Å molecular sieve. After cooling, filter off the molecular sieve and then add concentrated hydrochloric acid to take the pH to 2. Evaporate the solution to dryness under vacuum and take up the residue in water. The aqueous phase is washed with ethyl ether and then alkalinised by adding concentrated potassium hydroxide solution so that the pH is above 10. Extract twice with methylene chloride, wash with saturated sodium chloride solution, dry over anhydrous magnesium sulphate and then concentrate under vacuum to obtain α-cyclopropylbenzylamine, which is used without any further purification in the next step.

Provenance & Evidence