Triphenylphosphine → 4-(1-Oxo-1,2,3,4-tetrahydro-pyrazino[1,2-a]indol-8-yloxy)-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

To the solution of 0.5 g (2.5 mmol) 8-hydroxy-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one (example 1, intermediate a)) in 10 mL tetrahydrofuran, 0.6 g (3.0 mmol) 1-(tert-butoxycarbonyl)-4-hydroxypiperidine and 0.78 g (3.0 mmol) triphenylphosphine were added. The solution was cooled to 0° C., 0.68 g (3.0 mmol) di-tert-butyl azodicarboxylate were added and the cooling bath was removed. After 18 hours the reaction mixture was evaporated and the residue was flash-chromatographed on silica gel with dichloromethane:methanol:ammonia (9:1:0.1 v/v) as eluant to give 0.46 g (49%) of the desired compound as a white solid.

Provenance & Evidence