Condensation of Ortho-phenylenediamines and Phenylhydrazines with Ethyl 4-Chloro-3-oxobutanoate: A Facile Approach for the Synthesis of Substituted 1H-Benzimidazoles, Pyrazolones, and Pyrazoles

Abstract

Substituted 1H-benzimidazoles, pyrazolones, and pyrazoles have been synthesized by the condensation of ortho-phenylenediamines and phenylhydrazines, respectively, with ethyl 4-chloro-3-oxobutanoate in good yields. The present approach is novel, straightforward, and being reported for the first time with ethyl 4-chloro-3-oxobutanoate.

GRAPHICAL ABSTRACT

Keywords:

• Ethyl 4-chloro-3-oxobutanoate
• Lewis acids
• pyrazoles
• pyrazolones
• substituted 1H-benzimidazoles

ACKNOWLEDGMENTS

The authors thank M. Lakshmi Kantam, Director, and S. Chandrasekhar, Head, Natural Products Chemistry Division, Council of Scientific and Industrial Relations–Indian Institute of Chemical Technology (CSIR-IICT), for their constant encouragement.

SUPPLEMENTARY MATERIAL

Spectral data for the synthesized compounds can be accessed on the publisher’s website.