Trifluoroacetic acid → 1-[2-(4-Aminopiperidin-1-yl)ethyl]-2-oxo-1,2-dihydroquinoline-7-carbonitrile

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Reaction Steps

A solution of tert-butyl{1-[2-(7-cyano-2-oxoquinolin-1(2H)-yl)ethyl]piperidin-4-yl}carbamate (Intermediate 15) (6.57 g, 16.57 mmol) in dichloromethane (100 mL) was treated with trifluoroacetic acid (40 mL) at 0° C. for 30 minutes. The solvent was removed under reduced pressure and the residue codistilled once with dichloromethane, then taken up in dichloromethane (200 mL) and washed with saturated sodium hydrogencarbonate solution (50 mL, pH adjusted to 10 with sodium hydroxide). The aqueous phase was back-extracted three times with dichloromethane (3×100 mL) and dried over sodium sulfate. The solvent was removed under reduced pressure to give the product as off-white solid, 5 g, mp 138° C.

Provenance & Evidence