[On derivatives of 4-oxo-3,4-dihydropyrido[2,3-d]pyrimidine (author's transl)].

A typical representative of the hypnotic and anticonvulsive 4-quinazoline group is methaqualone (1). A number of new derivatives of 4-oxo-3,4-dihydropyrido[2,3-d]pyrimidine (10) were synthetized by substituting the benzene ring in the quinazolone molecule by the pyridine ring. The synthesis was achieved by the condensation of 2-acetaminonicotinic acid (9) and a primary amine or by the reaction of 2-aminonicotinic acid (8) with acetic acid and a primary amine. These new compounds were tested on animals for antiphlogistic, analgetic and antipyretic activities and for effects on the central nervous system as well. It was tried to establish, on the basis of the results obtained, relations between the chemical constitution and the pharmacological efficacy. It was found that, depending on the nature of the substituents in the position 3; either the antiphlogistic, analgetic and antipyretic effects or the anticonvulsive action will prevail.