Microwave-Assisted One-Pot Telescoped Synthesis of 2-Amino-1,3-thiazoles, Selenazoles, Imidazo[1,2-a]pyridines, and Other Heterocycles from Alcohols
Pablo Macías-Benítez, Alfonso Sierra-Padilla, Francisco M. Guerra*, F. Javier Moreno-Dorado
*Departamento de Química Orgánica e Instituto de Biomoléculas, Facultad de Ciencias, Universidad de Cádiz, Polígono Río San Pedro, 11510 Puerto Real, Cádiz, Spain, Email:
francisco.guerra
uca.es
P. Macías-Benítez, A. Sierra-Padilla, F. M. Guerra, F. J. Moreno-Dorado, J. Org. Chem., 2024, 89, 4628-4645.
DOI: 10.1021/acs.joc.3c02903
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Abstract
Primary and secondary alcohols have been converted into 2-amino-1,3-thiazoles under microwave irradiation, employing trichloroisocyanuric acid (TCCA) as a dual oxidant and chlorine source, TEMPO as a co-oxidant, and thiourea. While primary alcohols required a two-stage, one-pot procedure, secondary alcohols underwent a single-stage, one-pot conversion process.
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Details
The article discusses a microwave-assisted, one-pot telescoped synthesis method for creating various heterocycles, including 2-amino-1,3-thiazoles, selenazoles, imidazo[1,2-a]pyridines, and others, from primary and secondary alcohols. The process uses trichloroisocyanuric acid (TCCA) as a dual oxidant and chlorine source, TEMPO as a co-oxidant, and thiourea. Secondary alcohols undergo a single-stage conversion, while primary alcohols require a two-stage process, both completed within 25-45 minutes. This method is versatile, allowing the synthesis of different heterocycles by substituting thiourea with other nucleophiles. The study highlights the importance of developing environmentally friendly synthesis methods for pharmacologically active heterocycles, which are crucial in drug development. The optimized conditions for the reactions were identified using octan-1-ol as a test substrate, achieving up to 95% yield. The method's efficiency and versatility make it suitable for synthesizing complex heterocycles with potential biological activity, demonstrating significant advancements in the field of organic chemistry. The research was supported by various grants and acknowledges contributions from multiple authors affiliated with the University of Cádiz.
Key Words
thiazoles, microwave synthesis, TCCA
ID: J42-Y2024
