Pyrrolidone and piperidone derivatives with antihistaminic and antianaphylactic activities. Synthesis and pharmacological study

: The preparation of several derivatives to oxatomide (A), with the benzimidazolinone moiety replaced by another heterocyclic residue is described. In some cases changes to the basic chain of (A) were also considered. All the new compounds were evaluated as antihistaminics (H1) and antianaphylactics. The derivatives where the heterocyclic moiety was an unsubstituted or phenylsubstituted 2-pyrrolidone or 2-piperidone residue showed antihistaminic and antianaphylactic activities similar to those of oxatomide while modification of the basic side chain with elimination of the benzhydryl group, gave a complete loss of activity. The pharmacological screening was completed by the evaluation of the barbiturate induced sleep prolongation and of acute toxicity.