Sankyo Company, Limited

Takao Kinoto

Kazuo Sato

Toshiaki Yanai

Anthony Cornelius O'Sullivan

Bruno Frei

Hideo Takeshiba

Toshimitsu Toyama

Teruomi Jojima

Shigeru Mio

Keiji Tanaka

Akira Nishida

Compounds having a 16-membered macrolide ring, and related to the milbemycins and avermectins, with substituents at positions 5.13, 25 and optionally also 23, have acaricidal, insecticidal and anthelmintic properties. They are useful for treating various pests in plants and animals.

Macrolide compounds, their preparation and their use

13-Hydroxy-5-ketomilbemycin derivatives are prepared by oxidizing a 5-ketomilbemycin with selenium dioxide in the presence of a lower aliphatic carboxylic acid. A range of new 13-acyloxy-5-ketomilbemycins and a method of preparing them are also disclosed.

Process for preparing milbemycin derivatives and certain novel compounds

Compounds having a 16-membered macrolide ring, and related to the milbemycins and avermectins, with substituents at positions 5, 13, 25 and optionally also 23, have acaricidal, insecticidal and anthelmintic properties. They are useful for treating various pests in plants and animals.

13-Hydroxy-5-ketomilbemycin derivatives are prepared by oxidizing a 5-ketomilbemycin with selenium dioxide in the presence of a lower aliphatic carboxylic acic. A range of new 13-acyloxy-5-ketomilbemycins and a method or preparing them are also disclosed.

Process for preparing 13-hydroxy-5-ketomibemycin derivatives having

Compounds of formula (I): ##STR1## (in which R.sup.1 and R.sup.3 are hydrogen or halogen: R.sup.2 is hydrogen, alkyl, alkoxy or halogen; R.sup.4 is hydrogen and R.sup.5 is hydroxy or alkoxy; or R.sup.4 is hydroxy and R.sup.5 is hydrogen; except that R.sup.1, R.sup.2 and R.sup.3 may not all simultaneously be hydrogen) are valuable agricultural fungicides.

Pyridazinone derivatives and their use as agricultural fungicides

Compounds of formula (I): ##STR1## [wherein R.sup.1 and R.sup.3 represent hydrogen or halogen atoms, R.sup.2 represents a hydrogen or halogen atom or a lower alkyl or alkoxy group (provided R.sup.1, R.sup.2 and R.sup.3 are not simultaneously hydrogen), represents a single or double carbon-carbon bond and, where it is a single bond, R.sup.4 represents a group of formula --SR.sup.5 (wherein R.sup.5 represents an optionally substituted alkyl, phenyl, aralkyl or pyridyl group or a lower alkenyl group) and, where it is a double bond, R.sup.4 represents hydrogen] can be prepared by reacting a compound of formula (II): ##STR2## with a compound of formula R.sup.6 H [where R.sup.6 represents a group --SR.sup.5, a group --SR.sup.7 (where R.sup.7 represents a group of formula ##STR3## and Y represents oxygen or sulphur, R.sup.8 and R.sup.9 represent lower alkoxy groups and R.sup.10 represents a lower alkoxy, lower alkyl or phenyl group), a methoxy group or a halogen atom] to give a compound of formula (IV): ##STR4## or, where R.sup.6 represents a methoxy group, a methyl ester thereof; reacting this compound with hydrazine to give a compound of formula (V): ##STR5## 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 R.sup.6 represents a group of formula --SR.sup.5 are novel compounds.

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Shiga, Japan

Takao Kinoto