| abstract |
Provided herein is an impurity of eletriptan, eletriptan N-oxide, (R)-5-[2- (phenylsulfonyl)ethyl]-3 -[(1 -methyl-2-pyrrolidinyl-N-oxide)methyl]- 1H-indole, and a process for the preparation and isolation thereof. Provided further herein is a highly pure eletriptan or a pharmaceutically acceptable salt thereof substantially free of eletriptan N- oxide impurity, processes for the preparation thereof, and pharmaceutical compositions comprising highly pure eletriptan or a pharmaceutically acceptable salt thereof substantially free of eletriptan N-oxide impurity. |