PROCESS FOR PRODUCING ANTIFUNGAL PYRIDAZINONE DERIVATIVES AND CERTAIN NOVEL COMPOUNDS PRODUCED BY SUCH A PROCESS

摘要

Compounds of formula (I): (I) [wherein R1 and R3 represent hydrogen or halogen atoms, R2 represents a hydrogen or halogen atom or a lower alkyl or alkoxy group (provided R1, R2 and R3 are not simultaneously hydrogen), represents a single or double carbon-carbon bond and, where it is a single bond, R4 represents a group of formula -SR5 (wherein R5 represents an optionally substituted alkyl, phenyl, aralkyl or pyridyl group or a lower alkenyl group) and, where it is a double bond, R4 represents hydrogen] can be prepared by reacting a compound of formula (II): (II) with a compound of formula R6H [where R6 represents a group -SR5, a group -SR7 (where R7 represents a group of formula and Y represents oxygen or sulphur, R8 and R9 represent lower alkoxy groups and R10 represents a lower alkoxy, lower alkyl or phenyl group), a methoxy group or a halogen atom] to give a compound of formula (IV): (IV) or, where R6 represents a methoxy group, a methyl ester thereof; reacting this compound with hydrazine to give a compound of formula (V): (V) or (VI): (VI) and, if necessary, treating the compound of formula (V) with an acid or a base to produce the compound of formula (VI). All of the compounds of formula (I) are valuable antifungal agents and compounds of formula (V) where R6 represents a group of formula -SR5 are novel compounds.