Trifluoroacetic acid → HCID 67481463, compound

Participants

Reaction Conditions

Reaction Steps

TFA (14.75 g, 9.966 mL, 129.4 mmol) was added to a stirred solution of tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylate (5000 mg, 16.17 mmol) in DCM (40 mL) at 0° C. and the reaction stirred at this temperature for 1.5 hours. The solvent was removed in vacuo and the residue azeotroped with MeCN (×3). The residue was re-dissolved in DCM (50 mL) and cooled to 0° C. Et3N (6.545 g, 9.015 mL, 64.68 mmol) was added followed by a solution of propionyl chloride (1.646 g, 1.546 mL, 17.79 mmol) in DCM (5 mL). The reaction mixture was allowed to warm to ambient temperature over 1 hour. The mixture was diluted with DCM and washed with 1:1 1M HCl/brine (×2), dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by column chromatography (ISCO Companion™, 120 g column, eluting with 20 to 80% EtOAc/Petroleum Ether) to give the sub-title product as a white solid (3.87 g, 90% Yield). 1H NMR (400.0 MHz, CDCl3) δ 1.15 (t, 3H), 1.27 (s, 12H), 2.20-2.44 (m, 4H), 3.47 (t, 1H), 3.64 (s, 1H), 4.06 (d, 2H) and 6.48 (d, 1H) ppm; MS (ES+) 266.3.

Provenance & Evidence