PYRIDINE COMPOUND

PURPOSE:To obtain a new compound having a platelet agglutination inhibitory effect and a serotonin receptor antagonism and useful as a preventive and therapeutic agent for cerebral thrombosis, cardiac infarction, peripheral circulatory disorders, etc., an antiemetic and a psychotropic agent. CONSTITUTION:A compound of formula I (R is H or a 1 to 4C alkyl; R is H, a halogen or a 1 to 4C alkyl; A is a direct bond or methylene; Y is a substituted amino or a substituted carbamoyl; n is 0 or 1; The dotted line represents a single bond or a double bond), e.g. 3-(4-methyl-1-piperazinyl) methyl-6-(2-pyridyl)-3,4-dihydro-2H-1-benzopyran-4-one. The compound of formula I can be synthesized by conducting a Mannich reaction between a compound of formula II and a compound of formula NHR R (R and R are each H, a 1 to 4C alkyl or a cycloalkyl. A heterocycle may be formed by bonding R to R together with N) in the presence of formalin or paraformaldehye in a solvent (e.g. acetic anhydride) at 0 to 100 deg.C.