Microwave-assisted solvent-free synthesis of 3-[(4-substituted piperazin-1-yl)alkyl] imidazo[2,1-b][1,3]benzothiazol-2(3H)-ones as serotonin3 (5-HT3) receptor antagonists.
A series of novel 3-[(4-substituted piperazin-1-yl)alkyl]imidazo[2,1-b][1,3]benzothiazol-2(3H)-ones were prepared by microwave irradiation using alumina as solid support and also by a conventional method. The compounds were characterized by spectral data and the purity was ascertained by microanalysis. The synthesized compounds were evaluated for 5-hydroxytryptamine3 antagonisms in a longitudinal muscle-myenteric plexus preparation from guinea pig ileum against the 5-hydroxytryptamine3 agonist, 2-methyl-5-hydroxytryptamine. Among the test compounds, 3-[2-(4-methylpiperazin-1-yl)ethyl]imidazo[2,1-b][1,3]benzothiazol-2(3H)-one (3b) showed most favorable 5-hydroxytryptamine3 antagonism (pA2 6.7) in the isolated guinea pig ileum.
Pharmacy Group, Birla Institute of Technology and Science, Pilani, India. rmahesh@bits-pilani.ac.in
R
R
Mahesh
R Venkatesha
RV
Perumal
P V
PV
Pandi
D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002855:Chromatography, Thin Layer; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D007093:Imidazoles / Q000138:chemical synthesis* / Q000494:pharmacology*; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D008872:Microwaves; D009119:Muscle Contraction / Q000187:drug effects; D044406:Receptors, Serotonin, 5-HT3 / Q000187:drug effects*; D012702:Serotonin Antagonists / Q000138:chemical synthesis* / Q000494:pharmacology*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013844:Thiazoles / Q000138:chemical synthesis* / Q000494:pharmacology*
D007093:Imidazoles; D007202:Indicators and Reagents; D044406:Receptors, Serotonin, 5-HT3; D012702:Serotonin Antagonists; D013844:Thiazoles