The Leuckart Reaction

Abstract

The Leuckart reaction is a process for reductive alkylation of ammonia or primary or secondary amines by certain aldehdyes and ketones, It is distinguished by the fact that the reduction is accomplished by formic acid or a derivative of formic acid and should be compared with reductive alkylation discussed elsewhere in this series. The reaction is carried out by heating a mixture of the carbonyl compound and the formic acid salt or formyl derivative of ammonia or the amine. Primary and secondary amines produced in the reaction often are obtained as the formyl derivatives and must be recovered by hydrolysis; tertiary amines are obtained as formate. Modifications of this reaction are discussed. Keywords: Leuckart reaction; formaldehyde; aldehydes; ketones; quinones; pyrazolone; oxindole; ammonium formate; reductive alkylation. amines; experimental procedures