Process for preparing carboxamide oximes
US6020498A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1999 |
| Grant date | Feb 1, 2000 |
| Priority date | — |
| Expiry date | Jul 22, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D231/40
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to a process for preparing carboxamide oximes of the formula (I): in which R.sup.1 represents an aryl or heteroaromatic group, and R.sup.2 and R.sup.3 represent a hydrogen atom or groups as defined in the description, characterized by the three following steps: PA1 1) An amide of the formula (II) R.sup.1 CONHR.sup.4, with R.sup.1 having the previous meaning and R.sup.4 being a C.sub.1 to C.sub.8 alkyl group, is reacted with a chlorinating agent in order to obtain the corresponding chloroimine, PA1 2) The resulting chloroimine is then caused to react with an aminopyrazole in order to obtain a novel disubstituted amidine, PA1 3) The resulting amidine is caused to react with hydroxylamine or one of its salts. Carboxamide oximes are prepared more rapidly, and in a good yield, in this way. They are useful as synthesis intermediates, in particular for preparing photographic developing agents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.