A Facile, Sequential Multicomponent Approach to N-Aminoamidinothioureas—Versatile Synthons to Bioactive Heterocycles

Abstract

A sequential, three-component approach for the rapid and convenient one-pot synthesis of N-aminoamidinothioureas is reported. The improved synthetic strategy involves the selective blocking of amino functionality in aminoguanidine by Schiff base formation with carbonyl compounds to generate corresponding N-(alkylidene/arylidene)aminoguanidines and their subsequent in situ condensation with isothiocyanate. The structural motif incorporates three points for diversity multiplication, making it a suitable candidate for combinatorial synthesis. The generality of the improved procedure was established by synthesizing a series of diverse compounds through solution phase parallel synthesis by varying the carbonyl and isothiocyanate components. The newly synthesized compounds were characterized by spectral methods. The developed synthetic procedure employs mild reaction conditions, and individual steps are carefully optimized for easy automation.

Keywords:

• N-Aminoamidinothiourea
• combinatorial synthesis
• condensation
• diversity
• sequential multicomponent reaction

Acknowledgments

The author thanks University Grants Commission, Government of India for financial assistance, and Prof. K. N. Rajasekharan and Dr. Mercyamma Francis for useful discussions and support.