Reactions of (E)-O-Arylbenzaldoximes with Secondary Amines in Acetonitrile. Competition between E2 and SNAr Reactions

Article abstract of DOI:10.1021/jo00019a008

Reactions of (E)-O-arylbenzaldoximes in which the O-aryl group is 2,4-dinitrophenyl (1) and picryl (2) with secondary amines in acetonitrile have been studied kinetically.The reactions proceed via competing E2 and S_NAr mechanism.The second rate-determining step of the S_NAr reactions involves both uncatalyzed and base-catalyzed pathways.The sensitivity of the S_NAr reaction to base catalysis was greater for 2 and increased with base strength.The rates of E2 and S_NAr reactions increased by approximately 10₃ and 10₄ fold, respectively, with the variation of the substrate from 1 to 2.The yield of S_NAr product increased wit h base concentration, electron-withdrawing ability of O-aryl group, and base strength.From these results, factors that influence the competition between E2 and S_NAr reaction pathways are assessed.