Hydrogen Bromide → Eletriptan Hydrobromide

Participants

Reaction Conditions

Reaction Steps

3-{[1-Methylpyrrolidin-2(R)-yl]methyl}-5-(2-phenylsulphonylethyl)-1H-indole (15 kg) and 2-butanone (204 kg) were charged to a dry, glass-lined vessel. A solution of 48% aqueous hydrobromic acid (6.45 kg) in 2-butanone (63 kg) was added and the resulting slurry was subjected to azeotropic distillation until a volume of 150 litres remained. The reaction mixture was cooled to 17.5° C. and the product was isolated by filtration. The product was washed with 2-butanone (16 kg) to yield the α-polymorphic form of 3-{[1-Methylpyrrolidin-2(R)-yl]methyl}-5-(2-phenylsulphonylethyl)-1H-indole hydrobromide (18.2 kg wet, 17.5 kg when dry, 96.3%).

Provenance & Evidence