Synthesis 2007(2): 263-270  
DOI: 10.1055/s-2006-958941
PAPER
© Georg Thieme Verlag Stuttgart · New York

Novel and Efficient Synthesis of 2-Aminooxazoles from Pyrimidin-2(1H)-one

Vadim L. Alifanov, Eugene V. Babaev*
Chemistry Department, Moscow State University, Moscow 119992, Russian Federation
Fax: +7(495)9393020; e-Mail: babaev@org.chem.msu.su;
Further Information

Publication History

Received 21 August 2006
Publication Date:
14 December 2006 (online)

Abstract

Stepwise conversion of pyrimidin-2(1H)-one to 2-amino-5-aryloxazoles via oxazolo[3,2-a]pyrimidinium salts is reported. The sequence involves, (i) regioselective N-alkylation of pyrimidone by phenacyl bromides, (ii) cyclization of obtained 1-(2-aryl-2-oxoethyl)pyrimidin-2(1H)-ones into oxazolo[3,2-a]pyrimidinium salts under the action of fuming sulfuric (or triflic) acid, and (iii) reaction of the obtained salts with hydrazine leading to 2-amino-5-aryloxazoles.