Process for the preparation of o-chloromethyl-phenylglyoxylic acid derivatives
US5756811A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1996 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Dec 30, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/02
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
There is described a process for the preparation of a compound of formula I ##STR1## in which process: a) a compound of formula II ##STR2## is reacted with an organolithium compound of formula III EQU Li--R.sub.7 (III) PA1 b) the resulting lithium complex is reacted with a compound of formula IV EQU Y.sub.1 --CO--CO--Y.sub.1 IV PA1 to form a compound of formula V ##STR3## c) that compound is, in either order, c1) oximated with O-methylhydroxylamine; or oximated with hydroxylamine and then methylated or fluoromethylated or difluoromethylated; PA2 c2) reacted with a chloroformic acid ester. PA1 X, m, Y, R.sub.1 to R.sub.3 and R.sub.7 are as defined in the description.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.