Intermediate compounds and processes for the preparation of quinoline derivatives such as laquinimod sodium
The present invention relates to processes for the preparation of quinoline-3-carboxamide derivatives, such as sodium 5-chloro-3-(ethylphenylcarbamoyl)-1-methyl-2-oxo-1,2-dihydroquinolin-4-olate (Laquinimod sodium). The present invention further relates to intermediates formed in such processes.
1. A compound represented by the structure of formula (9):
wherein R is an alkyl, aryl or alkylaryl.
2. The compound according to claim 1 , wherein R is methyl, ethyl or benzyl.
3. A compound selected from the group consisting of:
a compound represented by the structure of formula (10):
and
a compound represented by the structure of formula (11):
wherein Y is a leaving group.
4. The compound according to claim 3 , wherein Y is selected from the group consisting of halogen, sulfonyloxy, O-benzotriazole (OBt), succinimido-oxy (ONSu), OR a wherein R a is an alkyl, aryl or alkylaryl, and OC(O)R b wherein R b is an alkyl, aryl or arylalkyl.