Phenylboronic Acid → 2-Ethoxy-4-(3-((S)-3-methy-1-(2-piperidin-1-yl-phenyl)-butylamino)-2-oxo-propyl)-benzoic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

In a round bottom flask fitted with a dean stark condenser, 3-Ethoxy-4-ethoxycarbonyl phenyl acetic acid (10.26 g, 0.0426 mol) was dissolved in toluene (100 ml) followed by slow addition of phenylboronic acid (0.494 g, 0.0040 mol) and (S)-3-methyl-1-(2-piperidinophenyl)-1-butylamine (10 g, 0.0406 mol). The reaction mixture was refluxed for 16-18 hours. The resulting mass was cooled at 25-30° C. followed by filtration. The toluene layer was washed with water and 1% sodium bicarbonate solution followed by complete distillation of toluene. Hexane (50 ml) was added to the resulting residue after complete removal of toluene in order to precipitate the solid, with stirring for 1 hour. The resulting solid was filtered and washed with hexane (10 ml). The wet material was further dried at 50-55° C. under vacuum for 4-6 hours to produce Ethyl (S)-2-ethoxy-4-[N-(1-(2-piperidino-phenyl)-3-methyl-1-butyl)-aminocarbonylmethyl]benzoate (Yield=89.6%; HPLC Purity: 99.66%).

Provenance & Evidence