Trifluoroacetic acid → 145815-98-1

Participants

Reaction Steps

Trifluoroacetic acid (TFA) (3.3 mL) was added dropwise to a cold (0° C.) solution of the piperidine formed in step e (0.50 g, 1.30 mmol) in CH2Cl2 (13 mL). After 30 min, the mixture was concentrated and excess TFA was removed by concentrating from toluene (2 to 3 times). The crude residue was dissolved in DMF (12.5 mL) and sodium carbonate (Na2CO3) (0.689 g, 6.50 mmol) and benzyl bromide (0.186 mL, 1.56 mmol) were added. The resulting mixture was stirred at room temperature for 4 hours. The reaction was filtered and the filtrate was concentrated in vacuo. The residue was dissolved in methylene chloride and washed with brine, and dried (MGSO4), filtered, and concentrated. Purification by silica gel chromatography (CH2Cl2→10% methanol/CH2Cl2) gave the title compound (free base) (0.343 g, 70%) as a white solid.

Provenance & Evidence