Trifluoroacetic acid → HCID 51049976, compound

Participants

Reaction Steps

N,N-Carbonyldiimidazole (790 mg, 4.87 mmol) (Fluka Chemie AG) was added to a solution of 2-phenylethynyl-thiazole-5-carboxylic acid (1.00 g, 4.36 mmol) [Intermediate 1] in tetrahydrofuran (17.4 mL) and stirred for 60 minutes. Piperidine (3.03 g, 35.6 mmol) and trifluoroacetic acid (295 μL, 3.83 mmol) were added and the mixture was stirred for 20 hours. The yellow solution was diluted with 150 mL of EtOAc and washed with 3.7 M HCl solution (5×30 mL), water (1×30 mL), 1.0 M K2CO3 (4×30 mL), water (2×30 mL), brine (1×30 mL), dried (Na2SO4) and concentrated to give a light tan solid (94% pure by LC/MS). The sample was further purified by silica gel chromatography over a 40 g SiO2 column using a gradient elution from 25% EtOAc in hexanes to 30% EtOAc in hexanes over 30 minutes to give title compound (2-phenylethynyl-thiazol-5-yl)-piperidin-1-yl-methanone (797 mg, 62%) as a light yellow powder. 1H NMR (300 MHz, CDCl3) δ 7.94 (s, 1H), 7.63-7.59 (m, 2H), 7.46-7.36 (m, 3H), 3.69-3.67 (m, 4H), 1.78-1.62 (m, 6H). LCMS (Method 1), RT=1.41. Calculated [M+H]+=297; Observed [M+H]+=297.

Provenance & Evidence