A new strategy for the preparation of secondary amines via o-(tetrahydropyranyloxymethyl)-benzamides

The new synthesis strategy for the preparation of secondary amines starts from N-alkyl-phthalimides which are reduced to the corresponding o-hydroxymethyl-N-alkyl-benzamides. After protection of the hydroxy group as tetrahydropyranyl ether the N-alkyl-benzamides are alkylated to o-(tetrahydropyranyloxymethyl)-N,N-dialkyl-benzamides. The deprotection of the hydroxy group and the release of the secondary amines can be achieved in excellent yields in one reaction step using aqueous acetic acid. (C) 1998 Elsevier Science Ltd. All rights reserved.