The Reaction of N-(Mesyloxy)phthalimide and N-(Mesyloxy)succinimide with Various Amines

Abstract

The reaction routes to N, N'-disubstituted o-ureidobenzamides [ 1 ] and 3-substituted quinazoline-2, 4-diones [ 2 ] by the reaction of N- (mesyloxy) phthalimide (MSOP) with various amines have been investigated. The reaction of MSOP with aniline at room temperature using pyridine as an acid acceptor gave o- (N'-phenylureido)benzanilide [1 a], while the reaction in the presence of triethylamine afforded 3-phenylquinazoline-2, 4-dione [2 a]. MSOP reacted with benzylamine in the presence of triethylamine to form N-benzyl-o- (N'-benzylureido) - benzamide 11 131 The reaction solvents had almost no influence on the proportion of the reaction products, [1] and [ 2 ] while it was affected by basicity of both the amines and the acid acceptors used in the reaction. Based on these results, it can be concluded that the reaction follows path A in which [ 1 ] is formed by the intermolecular addition of the intermediate o-isocyanatobenzamides C 6 with another molecule of the amine, and path B forming [ 2 ] by the intramolecular addition of [6]. On the other hand, the reaction of N- (mesyloxy) succinimide with aniline and benzylamine under various reaction conditions was found to proceed almost exclusively through path A to yield 3- (N'-phenylureido)propionanilide [8 a] and N-benzy1-3- (N'-benzylureido)propionamide C8 bp, respectively.