Abdel-Rahman Farghaly

Synthesis and anticonvulsant activity of some new pyrazolo[3,4-b]pyrazines and related heterocycles.

A series of new pyrazolo[3,4-b]pyrazines containing, 1,2,4-oxadiazolyl, thiadiazolyl, imidazothiadiazolyl, thiazolidinonyl, substituents and other different substituents, was synthesized using 1,6-diphenyl-3-methyl-lH-pyrazolo[3,4-b]pyrazine-5-carbonitrile (2) as a starting material. Some of the newly prepared compounds were evaluated for their anticonvulsant activity. Compounds 9a, 13a-d and 14a at a dose of 10mg/kg showed very significant anticonvulsant activity and increased the latency time of PTZ-induced tonic seizures. Compound 9b showed significant effect.

Thieno[2,3-c]pyrazoles and related heterocycles

5-Chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxaldehyde (1) was converted, via the oxime 2, into the chloronitrile 3. Treatment of compound 3 with methyl thioglycolate gave the novel methyl 4-amino-3-methyl-1-phenyl-1H-thieno [2,3-c]pyrazole-5-carboxylate (4). This with 2,5-dimethoxytetrahydrofuran gave the pyrrolyl ester 5. Hydrazinolysis of the ester 5 gave the carbohydrazide derivative 6 which was used in the synthesis of substituted heterocycles.