(1,3-Dialkyl-5-amino-1H-pyrazol-4-yl)arylmethanones. A series of novel central nervous system depressants

Article abstract of DOI:10.1021/jm00377a003

A series of novel (1,3-dialkyl-5-amino-1H-pyrazol-4-yl)arylmethanones was synthesized. Pharmacological evaluation of these compounds demonstrated central nervous system depressant activity, potential anticonvulsant properties, and a low order of acute toxicity. In addition, selected compounds showed potential antipsychotic effects. This report focuses on the synthesis and structure-activity relationships of these compounds. (5-Amino-1-ethyl-3-methyl-1H-pyrazol-4-yl)(2-chlorophenyl)methanone was the most active compound against pentylene-tetrazole-induced convulsions. (5-Amino-1,3-dimethyl-1H-pyrazol-4-yl)(3-chlorophenyl)methanone also has a favorable anticonvulsant depression ratio. (5-Amino-1,3-dimethyl-1H-pyrazol-4-yl)(3-trifluoromethylphenyl)methanone, (5-amino-1,3-dimethyl-1H-pyrazol-4-yl)(3-thienyl)methanone and (5-amino-3-ethyl-1-methyl-1H-pyrazol-4-yl)phenylmethanone are very potent depressants. (5-Amino-1,3-dimethyl-1H-pyrazol-4-yl)(2-thienyl)methanone possessed marked central depressant activity without anticonvulsant activity and without impairment of motor functioning. (5-Amino-1,3-dimethyl-1H-pyrazol-4-yl)(2-fluorophenyl)methanone has a behavioral profile suggestive of antipsychotic activity and gave a positive Ames test result.