Hetrogenous Catalysis

Journal of Industrial and Engineering Chemistry 18 (2012) 1474–1481

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Journal of Industrial and Engineering Chemistry

journal homepage: www.elsevier.com/locate/jiec

9 Microwave assisted solvent free synthesis of a,a-bis (arylidene) cycloalkanones by sulfated zirconia catalyzed cross aldol condensation of aromatic aldehydes and cycloalkanones

Kirat Rawal, Manish Kumar Mishra *, Manish Dixit, Meka Srinivasarao

Department of Chemical Engineering and Shah-Schulman Center for Surface Science and Nanotechnology, Faculty of Technology, Dharmsinh Desai University, College Road, Nadiad – 387 001, Gujarat, India

A R T I C L E I N F O

A B S T R A C T

Article history: Received 15 November 2011 Accepted 9 February 2012 Available online 18 February 2012 Keywords: Acid catalysis Brønsted acidity Cross aldol condensation Claisen Schmidt reaction Microwave irradiation Sulfated zirconia

The catalytic application of sulfated zirconia as solid Brønsted acid catalyst was explored for cross aldol condensation reactions (Claisen Schmidt reaction). The synthesized catalyst was highly active for solvent 9 free synthesis of a,a-bis(arylidene)cycloalkanones by cross aldol condensation of aromatic aldehydes with cycloalkanones. The microwave assisted synthesis resulted increased yields of the products (79– 99%) at significantly lower reaction temperature (120–140 8C) and reaction time (20 min) as compared to the synthesis by thermal heating (63–96% yield at 170 8C after 4 h). The microwave irradiation afforded selectively cross aldol products. The catalyst could be easily regenerated and reused several times with similar efficiency. ß 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

1. Introduction

9 a,a-bis (arylidene) cycloalkanones are useful precursors to synthesize potentially bioactive pyrimidine derivatives [1], 2,7disubstituted tropones [2], and...