Trifluoroacetic acid → 3,4-Didehydronaratriptan

Participants

Reaction Conditions

Reaction Steps

2-(1H-indol-5-yl)-ethanesulfonic acid methylamide (100 g) was dissolved in ethanol (1000 ml) and N-methyl-4-piperidone (200 ml) was added thereto at 25° C. and a solution of trifluoroacetic acid in ethanol (10 ml in 100 ml) was added over a period of 1 hour. The reaction mass was refluxed for 18-24 hours and cooled to 40° C. The reaction mass was concentrated under vacuum to obtain a residue and water (1500 ml) was added. The mixture was cooled to 10-15° C. and pH of the reaction mass was adjusted to 8 using 5% sodium bicarbonate solution and stirred. The resulting solid was filtered and dried at 50-55° C. under vacuum to obtain title compound (Yield: 93 g, HPLC Purity: 99%)

Provenance & Evidence