Imidazo[2,1-b]benzothiazoles. II. Synthesis and antiinflammatory activity of some imidazo[2,1-b]benzothiazoles.
3-[2-[p-(Un)substituted phenyl]imidazo [2,1-b]benzothiazol-3- yl]propionic acid derivatives (2a--e) were prepared via the interaction of the corresponding 2-[p-(un)substituted phenyl]imidazo[2,1-b]benzothiazoles (1a--e) with acrylic acid in the presence of acetic anhydride and acetic acid. Esterification of 2a--e produced methyl esters (3a--e). Upon the interaction of 3a with m-chloroperbenzoic acid, the S-dioxide (4a) was obtained. Compound 5a was prepared from 4a by alkaline hydrolysis. Vilsmeier formylation for 1a--e produced novel [2-[p-(un)substituted phenyl]imidazo[2,1-b]benzothiazol-3- yl]formaldehyde derivatives (6a--e). Derivatives 6a--e reacted with ethyl bromoacetate to give ethyl 3-hydroxy-3-[2-[p-(un)substituted phenyl]imidazo[2,1-b]benzothiazol- 3-yl]propionate esters (7a--e). Compound dl-7a was resolved with l-(+)-tartaric acid. Compounds 2a--e showed weak or no activity in the carrageein-induced paw edema assay. Compound 4a significantly inhibited the leakage of pontamine-sky blue dye into the peritoneal cavity of mice, in the capillary permeability inhibition assay. Compound 5a inhibited the writhing by 62% in the acetic acid-induced writhing assay.
El-Shorbagi
A N
AN
Sakai
S
S
el-Gendy
M A
MA
Omar
N
N
Farag
H H
HH
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D007093:Imidazoles / Q000138:chemical synthesis* / Q000494:pharmacology; D051379:Mice; D051381:Rats; D013844:Thiazoles / Q000138:chemical synthesis* / Q000494:pharmacology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D007093:Imidazoles; D013844:Thiazoles