AROMATIC NUCLEOPHILIC-SUBSTITUTION REACTIONS OF O-ARYL OXIMES WITH PIPERIDINE AND HEXYLAMINE IN CYCLOHEXANE

A detailed study of piperidinolysis and hexylaminolysis of O-(2,4-dini trophenyl) benzophenone oxime, O-(2,4-dinitrophenyl)-p-chlorobenzophen one oxime and O-(2,4-dinitrophenyl)-p-bromobenzophenone oxime in cyclo hexane at different temperatures has been undertaken. The piperidinoly sis reactions show a third order dependence on amine and inverse tempe rature effect. The analysis of data indicates that the reactions proce ed through two routes; the rate of first route increases and of the se cond route decreases with temperature. The overall rate k(A) shows inv erse temperature effect due to predominating effect of the second rout e. The results support the Jack Hirst's concept of reaction mechanism in nonpolar solvents. In contrast to piperidinolysis, n-hexylaminolysi s reactions show only a. second order dependence on amine which has be en explained to be due to lesser stability of hydrogen bonded homoconj ugate acid BH+B involving long chain hexylamine molecules.