Synthesis and alkylation of 1-aryl-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones as possible anticonvulsant agents

Abstract

The synthesis of 1-(4-bromophenyl)- and 1-(2-chlorophenyl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidine-4-one as possible anticonvulsant agents was planned. It was carried out by the interaction of the corresponding phenylhydrazine hydrochloride with ethyletoxymethylencyanocetate with a further heating of obtained 5-аmino-1- аryl-1H-pyrazole-4-carboxylate in excess of formamide. The direction of reaction of 1-aryl-1,5-dihydro-4Hpyrazolo[ 3,4-d] pyrimidine-4-one with N-arylsubstituted α-chloracetamides, 2-chloro-1-(4-arylpiperazine-1-yl)- ethanone and 2-chloro-N-(4-chlorobenzyl)acetamide in the presence of DMFA-NaHCO3 had been investigated. Using the data of NMR and NOESY spectroscopy it was found out that reaction is selectively performed at 5 position of pyrazolo[3,4-d]pyrimidine system. Due to preliminary prognosis of biological activity pharmacological screening of substances synthesized as possible anticonvulsant agents on the penthyltetrazole seizures was planned