1379595-97-7Relevant articles and documents
An Efficient Method for the Synthesis of Laquinimod
Huang, Yanyan,Feng, Ying,Gao, Wensheng,Zhang, Chao,Chen, Ligong
, p. 437 - 440 (2016)
Laquinimod, 5-chloro-1,2-dihydro-N-ethyl-4-hydroxy-1-methyl-2-oxo-N- phenyl-3-quinoline carboxamide, is an oral drug in clinical trials for the treatment of multiple sclerosis. An efficient synthetic method for laquinimod from 2-amino-6-chlorobenzoic acid via four steps was established. The overall yield of laquinimod is up to 82% as compared with 70% reported in literature. It has also been demonstrated that green reagent dimethyl carbonate is not suitable for the N-methylation of 5-chloroisatoic anhydride owing to the ring-cleavage reaction induced by the generated methanol. The ring-cleavage by-products were isolated and characterized by 1H-NMR and 13C-NMR. In addition, in the study of laquinimod derivatives, we found that 5-chloro-1,2-dihydro-N-ethyl-4-hydroxy-1-methyl-2-oxo-N-phenyl-3-quinoline carboxamide (laquinimod) was obtained in much higher yield than 7-chloro-1,2-dihydro-N-ethyl-4-hydroxy-1-methyl-2-oxo-N-phenyl-3-quinoline carboxamide under the same reaction conditions, and it is possibly attributed to a neighboring group effect.