Synthesis 2019; 51(10): 2149-2156
DOI: 10.1055/s-0037-1610693
paper
© Georg Thieme Verlag Stuttgart · New York

Efficient Synthesis of 4,7-Dihydro-1H-oxepino[2,3-c]pyrazoles by Potassium Carbonate Promoted [4+3] Annulation of Crotonate-Derived Sulfur Ylides with Benzylidenepyrazolones

Dian Wang
a   State Key Laboratory of Elemento-Organic Chemistry, Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. of China   Email: miaozhiwei@nankai.edu.cn
,
Xue Wang
a   State Key Laboratory of Elemento-Organic Chemistry, Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. of China   Email: miaozhiwei@nankai.edu.cn
,
Xuange Zhang
a   State Key Laboratory of Elemento-Organic Chemistry, Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. of China   Email: miaozhiwei@nankai.edu.cn
,
a   State Key Laboratory of Elemento-Organic Chemistry, Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. of China   Email: miaozhiwei@nankai.edu.cn
b   Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, P. R. of China
› Author Affiliations
We thank the National Key Research and Development Program of China (2016YFD0201200), Tianjin Agricultural and Rural Work Committee (2016D01A016), and the State Key Laboratory of Elemento-Organic­ Chemistry in Nankai University for financial support.
Further Information

Publication History

Received: 28 October 2018

Accepted after revision: 16 January 2019

Publication Date:
19 February 2019 (online)


Dedicated in celebration of the 100th anniversary of Nankai University

Abstract

The [4+3] annulation reaction of crotonate-derived sulfur ylides with benzylidenepyrazolones using K2CO3 as the base is reported. The ready availability of starting materials and the simple cyclization procedure make this approach suitable for the preparation of a diverse array of 4,7-dihydro-1H-oxepino[2,3-c]pyrazoles in good to excellent yields.

Supporting Information