Synthesis of 3-Aryl-2-(2-aryl-2-oxoethyl)pyrido[2,3-d]-4(3H)pyrimidones and 3-Aryl-2-(2-arylethenyl)pyrido[2,3-d]-4(3H)pyrimidones as Potential Antiepileptic Drugs

A series of 2-alkyl-3-arylpyrido[2,3-d]pyrimidones were synthesized for testing as potential antiepileptic drugs. The goal was to achieve better neurological activity and/or lower toxicity than displayed by a series of 2-alkyl-3-aryl-4(3H)-quinazolinones prepared previously in our research group. From the pharmacological testing data of these target compounds, we have found that the additional nitrogen at the C-8 position of the quinazolinone framework increased the anticonvulsant activity. However, the neurological toxicity increased as well. The anticonvulsant and neurotoxic activity seen in the variuos 2-alkyl side chains and 3-aryl substituents incorporated into these new pyridopyrimidones was consistent with the activity observed with the same substituents on the 4(3H)-quinazolinones. The 3-aryl group consists of various ortho-substituted phenyl rings, while the 2-alkyl chain consists of a 2-(2-aryl-2-oxo)ethyl or 2-arylethenyl group.