Related Experiment Video
Updated: Jun 2, 2026

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines
Published on: June 23, 2019
A green expedient synthesis of pyridopyrimidine-2-thiones and their antitubercular activity
Stephen Michael Rajesh1, Raju Suresh Kumar, Lawzer Arun Libertsen
1Department of Organic Chemistry, School of Chemistry, Madurai Kamaraj University, Madurai 625 021, India.
Abstract:
The pseudo four-component domino reactions of N-substituted-4-piperidones, substituted aromatic aldehydes and thiourea in the presence of solid sodium ethoxide under solvent-free conditions afforded pyridopyrimidine-2-thiones in almost quantitative yields by simply grinding for 1-2 min. at ambient temperature. The synthesized compounds were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv. Among them, (E)-6-benzyl-8-(2,4-dichlorobenzylidene)-4-(2,4-dichlorophenyl)-3,4,5,6,7,8-hexahydropyrido[4,3-d]pyrimidine-2(1H)-thione (MIC 2.8 μM) displays the maximum activity, being 2.7 and 1.7 times more active than the first line antitubercular drugs ethambutol and ciprofloxacin, respectively, and less active than rifampicin and isoniazid, by 28 and 7 times, respectively.
Related Concept Videos
Antiprotozoal Agents
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
