Sodium Hydroxide → Laquinimod Sodium

Participants

Reaction Steps

N-Ethyl-N-phenyl-1,2-dihydro-4-hydroxy-5-chloro-1-methyl-2-oxoquinoline-3-carboxamide (15 gm) was suspended in isopropyl alcohol (100 ml) at 25-30° C. under stirring followed by the addition of freshly prepared sodium hydroxide solution (1.4 gm of sodium hydroxide in 3.5 ml of water) at 20-25° C. and then stirred for 15-30 minutes at 25-30° C. The resulting solution was filtered through a hyflow supercell bed and the bed was washed with isopropyl alcohol (50 ml) at 25-30° C. The resulting filtrate was stirred for 20 hours at 25-30° C. The resulting white colored solid was filtered, washed with chilled isopropyl alcohol (20 ml) and then dried in air oven at 60-65° C. to yield 9 gm of laquinimod sodium in crystalline Form A2 (HPLC Purity: 99.8%).

Provenance & Evidence