3(2H)-PYRIDAZINONES, PHARMACEUTICAL COMPOSITIONS CONTAINING THEM AND PROCESS FOR PREPARING SAME

摘要

NOVEL 3(2H)-PYRIDAZINONES, PHARMACUTICAL COMPOSITIONS CON TAINING THEM AND PROCESS FOR PREPARING SAME The invention relates to novel, racemic and optically active 3(2H)-pyridazinone derivatives of the general formula (I), (I) wherein R1 means hydrogen; a C1-4alkyl group optionally substituted by an R5R6N- group where R5 and R6, being the same or different, stand for a C1-4alkyl group or R5R6N- together represents a 6-membered heterocyclic group optionally containing an oxygen or an R7N- moiety where R7 is a C1-4alkyl optionally substituted by a phenyoxy group or a C3-5alkenyl optionally substituted by a phenyl grup; or a C1-4alkyl group substituted by a mono- or polysubstituted phenyl, phenoxy or benzyloxy group; or a C3-5alkenyl or C3-5alkynyl optionally substituted by an unsubstituted or optionally substituted phenyl group; or a phenyl group; R2 means hydrogen; or a C1-4alkyl optionally substituted by a morpholino, pyridyl, 1,4-benzodioxanyl or an optionally substituted phenyl group; R3 means hydrogen or an optionally substituted phenyl group; R4 means hydrogen; or R8CO- group where R8 is a C1-4alkyl, phenyl or pyridyl group or an amino group substituted by a C1-4alkyl group; or an -SO3M moiety where M is hydrogen or an organic or inorganic cation; X means halogen; and n is 1, 2 or 3, with the proviso that R1 is different from a C1-4alkyl, alkenyl, aralkyl and phenyl group when n is 1, as well as their tautomers and the acid addition salts of these compounds. The invention further relates to pharmaceutical compositions containing as active ingredient a compound of the general formula (I) as well as to a process for the preparation of compounds of the general formula (I). The compounds of the invention possess a significant calmodulin-antagonizing effect, decrease the coronary resistance and are less toxic. Thus, these compounds are useful for treating cardiovascular diseases, particularly angina pectoris.