Methanesulfonic Acid → Lurosetron mesylate

Participants

Reaction Conditions

Reaction Steps

6-Fluoro-2,3,4,5-tetrahydro-5-methyl-2-[(5-methyl-1H-imidazol-4-yl)methyl]-1H-pyrido[4,3-b]indol-1-one (224.9 g) was suspended in IMS (1125 ml) and heated to reflux. A solution of methanesulphonic acid (69.2 g) in IMS (675 ml) was added with stirring over 15 minutes. The mixture was subsequently allowed to cool over 3 hours, then seeded and left overnight at ambient temperature before being cooled to 4° C. for 5 hours, with stirring. The mixture was filtered, the solid washed with cold IMS (2×450 ml), and then dried between 40° and 76° C. in vacuo to give the title compound (226 g) as a crystalline solid.

Provenance & Evidence