Ethyl trifluoroacetate → HCID 69666019, compound

Participants

Reaction Conditions

Reaction Steps

THF (3.0 mL) and ethyl trifluoroacetate (1.32 mL, 1.58 g, 11.1 mmol) were added to sodium hydride (442 mg of 60% oil dispersion, 11.1 mmol) in a flask fitted with a mechanical stirrer and a reflux condenser. 1-(tert-butoxycarbonyl)-4-piperidineacetic acid ethyl ester (1.50 g, 5.52 mmol) dissolved in THF (2.0 mL) was added over 30 min, with additional THF (2×1 mL) to complete the transfer. The mixture was warmed to 45° C. overnight. An additional portion of ethyl trifluoroacetate (1.0 mL, 1.19 g, 8.4 mmol) was added the temperature was increased to 70° C. for 17 h. After cooling to RT, the mixture was partitioned between EtOAc (50 mL) and a mixture of saturated aq. NaCl (25 mL) and 2 N aq. HCl (10 mL). The aqueous layer was extracted with EtOAc (25 mL). The organic layers were washed in succession with saturated aq. NaCl (2×10 mL), dried (Na2SO4), decanted, and evaporated. The crude product was purified by flash column chromatography on silica gel, eluting with 90:10 to 85:15 v/v hexanes/EtOAc to give the title compound as a colorless oil. For the title compound: 1H NMR (500 MHz, CDCl3) showed an apparent mixture of tautomers; ESI-MS 268.2 (M+H−100); HPLC A: 3.3 min.

Provenance & Evidence