Synthesis 2008(21): 3478-3486  
DOI: 10.1055/s-0028-1083169
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Pyrazoles, Diazepines, Enaminones, and Enamino Esters Using 12-Tungstophosphoric Acid as a Reusable Catalyst in Water

Xiang Chena, Jin Shea, Zhicai Shang*a, Jun Wu*a, Haifeng Wua, Peizhi Zhangb
a Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. of China
Fax: +86(571)87952379; e-Mail: shangzc@zju.edu.cn;
b School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310012, P. R. of China
Further Information

Publication History

Received 4 June 2008
Publication Date:
16 October 2008 (online)

Abstract

12-Tungstophosphoric acid (H3PW12O40) is found to be an efficient and recyclable catalyst in promoting a chemo- and re­gioselective condensation of hydrazines/hydrazides, diamines, and primary amines with various 1,3-dicarbonyl compounds in pure water at room temperature to afford pyrazoles, diazepines, and enaminones/enamino esters, respectively, in high yields.