Patent · US Expired

Process for preparing substituted oxadiazolones

US5756752A · kind A · utility

1Cited by

2References

9Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Hans-Joachim Diehr · Wuppertal, DE
Reinhard Lantzsch · Leverkusen, DE
Jacqueline M. Applegate · Parkville, US
Klaus Jelich · Wuppertal, DE

Key dates

Filing date	Apr 15, 1997
Grant date	May 26, 1998
Priority date	—
Expiry date	Apr 15, 2017

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC07C241/04
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

Abstract

Substituted oxadiazolones of the formula (I) ##STR1## in which R represents optionally substituted alkyl, are obtained in good yields and high purity on reacting in a first step carboxylic acids of the general formula (II) EQU R--COOH (II) with hydrazine hydrate in the presence of a catalyst and an inert diluent at temperatures between 0.degree. C. and 150.degree. C. with elimination of water and removal of said catalyst and reacting the resulting carboxylic hydrazides of the general formula (III) EQU R--CO--NH--NH.sub.2 (III) in a second step with phosgene (COCl.sub.2) at temperatures between 20.degree. C. and 120.degree. C.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.