US 12,012,378 B2
Method for synthesizing 2-bromoglutaric acid diesters
Jean-Michel Paratian, La Rochelle (FR); and Martine Cerf, Breuil-Magné (FR)
Assigned to GUERBET, Villepinte (FR)
Appl. No. 18/011,683
Filed by GUERBET, Villepinte (FR)
PCT Filed Jul. 16, 2021, PCT No. PCT/EP2021/070022
§ 371(c)(1), (2) Date Dec. 20, 2022,
PCT Pub. No. WO2022/013440, PCT Pub. Date Jan. 20, 2022.
Claims priority of application No. 20305823 (EP), filed on Jul. 16, 2020.
Prior Publication US 2023/0303477 A1, Sep. 28, 2023
Int. Cl. C07C 69/63 (2006.01); C07C 67/08 (2006.01); C07C 67/307 (2006.01); C07C 67/54 (2006.01); C07D 307/33 (2006.01)
CPC C07C 69/63 (2013.01) [C07C 67/08 (2013.01); C07C 67/307 (2013.01); C07C 67/54 (2013.01); C07D 307/33 (2013.01)] 20 Claims
 
1. A process for preparing the 2-bromoglutaric acid diester of formula (I) below:

OG Complex Work Unit Chemistry
in which R represents a propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl or hexyl group,
wherein said process comprises the following steps:
(b) forming the 2-hydroxyglutaric acid diester of formula (II)

OG Complex Work Unit Chemistry
by reacting butyrolactone acid of formula (BA)

OG Complex Work Unit Chemistry
with the alcohol of formula ROH, in the presence of an acid;
(c) brominating the 2-hydroxyglutaric acid diester of formula (II), by sparging with gaseous hydrobromic acid, thereby leading to the 2-bromoglutaric acid diester of formula (I); and
wherein a degree of purity of the 2-bromoglutaric acid diester of formula (I), determined by HPLC analysis, is greater than or equal to 90%.