Novel and Efficient Catalytic Route for the Syntheses of Tetrahydrofurans Useful in the Preparation of Neonicotinoid Insecticides

Abstract

Neonicotinoids are good alternatives to the widely used organophosphate insecticides (OP) and have gained enormous importance because of their low toxicity in vertebrates. An environmentally benign route for the synthesis of 3‐(hydroxymethyl)tetrahydrofuran useful in the preparation of a neonicotinoid insecticide viz. MTI‐446 is described. Principles of green chemistry such as hydroformylation, single‐pot transketalization, and intramolecular cyclocondensation through catalytic reactions were adopted. The process reported here is superior to the existing methods with respect to lower salt formation and higher atom economy, and it was extended to the preparation of a novel intermediate, 3,3‐bis(hydroxymethyl)tetrahydrofuran, conceived to be useful in the preparation of new insecticides.

Keywords:

• Catalytic reactions
• hydroformylation
• neonicotinoids
• transketalization

Acknowledgments

We are grateful to UGC–New Delhi for providing fellowships to S.K.P. and A.R.R. We thank CSIR–New Delhi and IICT–Hyderabad for providing the facilities to work.