US 5,310,926 AGranted

Process for producing isoxazole derivatives

AssigneeTaiho Pharmaceutical Co., Ltd.

InventorsYu-ichi Hagiwara, Motoaki Tanaka, Makoto Kajitani, Mitsugi Yasumoto

Life of this patent

Estimating the term…

Loading patent…

Abstract

The present invention provides a process for producing isoxazole derivatives represented by the formula ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and are each a hydrogen atom or lower alkoxyl, and R.sup.3 is cyano or alkoxycarbonyl, the process being characterized by oxidizing an .alpha., .beta.-unsaturated ketoxime derivative represented by the formula ##STR2## wherein R.sup.1 , R.sup.2 and R.sup.3 are as defined above. The isoxazole derivatives (II) to be produced by the process of the present invention are useful as intermediates for preparing (3,4-diarylisoxazol-5-yl) acetic acid derivatives which are useful as anti-inflammatory agents, analgesics and antipyretics.

Claims3

Dependent claims

A process for producing an isoxazole derivative of the formula (II):

##STR10## wherein R.sup.1 and R.sup.2 are the same or different and are each a hydrogen atom or lower alkoxy and R.sup.3 is cyano or alkoxycarbonyl, comprising the steps of
a) reacting a desoxybenzoin derivative of the formula (III) ##STR11## with an alkoxyacrylonitrile or alkoxyacrylic acid derivative of the formula (IV)
ZO--.dbd.--R.sup.3 (IV)
wherein Z is a lower alkyl, in a suitable solvent in the presence of a base to produce a compound of the formula (V) ##STR12## b) then reacting the resulting compound of the formula (V) with hydroxylamine or a salt thereof in a suitable solvent at a temperature of 0.degree. to 200.degree. C. to obtain an .alpha., .beta. unsaturated ketoxime derivative of the formula (I) ##STR13## wherein R.sup.1, R.sup.2, and R.sup.3 are as defined above, and c) oxidizing the compound of the formula (I).

1 more element

Dependencies are inferred from the claim text.