Synthesis 2002(18): 2691-2700
DOI: 10.1055/s-2002-35982
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Novel 2,3-Dihydroimidazo[2,1-b][1,3]oxazoles Through Intramolecular Nucleophilic ipso-Substitution in 2-Alkylsulfonylimidazoles

Pilar Morenoa, Montserrat Herasa, Miguel Maestrob, José M. Villalgordo*a
a Departament de Química, Facultat de Ciències, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
Fax: +34(97)2418150; e-Mail: jose.villalgordo@udg.es;
b Servicios Xerais de Apoio a Investigación, Universidade da Coruña, Campus da Zapateira s/n, 15071, A Coruña, Spain
Further Information

Publication History

Received 18 July 2002
Publication Date:
06 December 2002 (online)

Abstract

Readily available 2-(benzylsulfanyl)imidazoles 6, were studied as potential precursors toward the synthesis of novel diversely substituted 2,3-dihydroimidazo[2,1-b][1,3]oxazoles. Thus, the reaction between enolates derived from 6 and different electrophiles as well as the addition of Grignard reagents to the carbonyl group in 6 were explored. The formation of the fused imidazoxazoles 20 under mild conditions was successfully accomplished taking advantage of the key role played by the 2-alkylsulfonyl moiety in 19 as an efficient leaving group in intramolecular nucleophilic ipso-substitution reactions.

26

Crystallographic data (excluding structure factors) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication No. CCDC-187224 (Compound 24). Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: +44 122 3336033; e-mail: deposit@ccdc.cam.ac.uk).