Synthesis and evaluation of anticonvulsant and antidepressant activities of 5-alkoxytetrazolo[1,5-c]thieno[2,3-e]pyrimidine derivatives.

A series of 5-alkoxytetrazolo[1,5-c]thieno[2,3-e]pyrimidine derivatives were synthesized and their anticonvulsant and antidepressant activities were evaluated. Pharmacological tests showed that four of the synthesized compounds had weak anticonvulsant activity, while most of the compounds had excellent antidepressant activity. The most active compound was 5-(2,4-dichlorobenzyloxy)tetrazolo[1,5-c] thieno[2,3-e]pyrimidine, which decreased the immobility time by 51.62% at a dose of 100 mg/kg. The results of open-field tests of this compound indicated that it had no significant effects on the locomotor activity compared with the control group at the doses assayed in the forced swimming tests test. This means that the antidepressant activity detected in the FST for the compound is not the result of central nervous system stimulant properties, and further confirms its antidepressant-like effect.