Metal-Free Synthesis of 2-N,N-Dialkylaminobenzoxazoles Using Tertiary Amines as the Nitrogen Source

© 2019 American Chemical Society. The unprecedented reaction of tertiary amines with 2(3H)-benzoxazolones has been investigated. In the presence of the Ph 3 P-I 2 reagent system, the reaction of both acyclic and cyclic aliphatic tertiary amines led to the formation of 2-N,N-dialkylaminobenzoxazoles...

Full description

Saved in:
Bibliographic Details
Main Authors: Mookda Pattarawarapan, Dolnapa Yamano, Nitaya Wiriya, Wong Phakhodee
Format: Journal
Published: 2019
Subjects:
Online Access:https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85065768637&origin=inward
http://cmuir.cmu.ac.th/jspui/handle/6653943832/65485
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Chiang Mai University
Description
Summary:© 2019 American Chemical Society. The unprecedented reaction of tertiary amines with 2(3H)-benzoxazolones has been investigated. In the presence of the Ph 3 P-I 2 reagent system, the reaction of both acyclic and cyclic aliphatic tertiary amines led to the formation of 2-N,N-dialkylaminobenzoxazoles with the selective cleavage of an alkyl group. Especially, N-(2-iodoethyl)piperazinyl derivatives were rapidly produced in good yields when using DABCO as the nitrogen source. Only in the cases when the nucleophilicity of the substrates exceeds that of the amine, competitive self-condensation of benzoxazolones then proceeds preferentially. 31 P{ 1 H}-NMR study suggested the involvement of an aryloxyphosphonium intermediate and/or possibly 2-iodobenzoxazole which activates the C-2 position of benzoxazolones toward nucleophilic aromatic substitution.