Trifluoroacetic acid → HCID 58706342, compound

Participants

Reaction Steps

To a solution of 4-(5-cyano-benzooxazol-2-ylamino)-piperidine-1-carboxylic acid tert-butyl ester (6.62 g, 19.33 mmol, 1.0 equiv) in dichloromethane (100 mL) was added trifluoro-acetic acid (7.4 mL, 11.03 g, 96.7 mmol, 5.0 equiv). After stirring under Ar at rt for 18 h excess trifluoro-acetic acid was removed under reduced pressure and the crude solid taken up in dichloromethane (100 mL) and water (100 mL). The pH was adjusted to 10 by addition of a conc. solution of K2CO3 and the solution extracted with dichloromethane/2-propanol (4:1, 3×50 mL). The combined organic phases were dried over MgSO4, the organic solvent evaporated under reduced pressure and the crude reaction product purified with column chromatography on silica eluting with a gradient of dichloromethane/methanol (100:0→95:5) containing 33% of NH4OH to yield 4.36 g (93%) of the title compound. MS (ESI): 243.1 [M+H]+.

Provenance & Evidence