Method for the preparation of 2-amino-6-ethylbenzoic acid
申请人:Active Biotech AB
公开号:EP2316818A1
公开(公告)日:2011-05-04
The present invention relates to a novel method for the production of 2-amino-6-ethylbenzoic acid wherein 7-amino-3-methylphtalide or 7-amino-3-hydroxy-3-methylphtalide is reduced to 2-amino-6-ethylbenzoic acid in water or in a mixture of a water miscible solvent and water at a pH of 7 or higher using a hydrogenation catalyst selected from Raney nickel and palladium based catalysts and using a hydrogen source selected from the group consisting of hydrogen gas, formic acid derivatives and cyclohexen. The invention also relates to 2-amino-6-ethylbenzoic acid produced with this method, and to use of such 2-amino-6-ethylbenzoic acid in the production of paquini-mod.
[EN] METHOD FOR THE PREPARATION OF 2-AMINO-6-ETHYLBENZOIC ACID<br/>[FR] PROCÉDÉ DE PRÉPARATION D'ACIDE 2-AMINO-6-ÉTHYLBENZOÏQUE
申请人:ACTIVE BIOTECH AB
公开号:WO2011054874A1
公开(公告)日:2011-05-12
The present invention relates to a novel method for the production of 2- amino-6-ethylbenzoic acid wherein7-amino-3-methylphtalide or 7-amino-3- hydroxy-3-methylphtalide is reduced to 2-amino-6-ethylbenzoic acid in water or in a mixture of a water miscible solvent and water at a pH of 7 or higher using a hydrogenation catalyst selected from Raney nickel and palladium based catalysts and using a hydrogen source selected from the group consisting of hydrogen gas, formic acid derivatives and cyclohexen. The invention also relates to 2-amino-6-ethylbenzoic acid produced with this method, and to use of such 2-amino-6-ethylbenzoic acid in the production of paquinimod.
Concise Process for Pyriftalid Synthesis by Introducing the Mercapto Group Directly from a Nitro Group
作者:Zhong Li、Yong-Jian Chi、Yi-Wen Huang
DOI:10.1021/acs.oprd.1c00384
日期:2022.2.18
A concise and efficient process for the synthesis of pyriftalid is described herein. The improved process features the direct introduction of the mercapto group by one-step substitution of a nitro group using sodium sulfide and elemental sulfur. A systematic study of the key step is also carried out in this article. Compared with previous routes, the optimized route is shorter and avoids a hazardous