Abstract
A series of substituted pyrazole derivatives were prepared from N1-[4-(cinnamoyl) phenyl]-5-chloro-2-methoxybenzamides 2a-c, which were prepared from N-(4-acetylphenyl)-5-chloro-2-methoxybenzamide as starting material. Treating of compound 2a-c with methylhydrazine or phenylhydrazine afforded the corresponding N-substituted pyrazoline derivatives 3a-c and 4a-c, respectively. The acryloyl derivatives 2a-c were reacted with hydrazine hydrate in dioxane afforded a pyrazoline 5a-c, which was acetylated with acetyl chloride in dioxane to yield the N-acetyl analogue 6a-c. In addition, pyrazoline 5c was reacted with morpholine in the presence of paraformaldehyde to give the corresponding N-substituted pyrazoline derivative 7. The structure assignments of the new compounds are based on chemical and spectroscopic evidence. The pharmacological screening showed that many of these compounds have less toxicity and good anti-inflammatory activities.