D-Tartaric acid → 2-Methyl-2-(2-methyl-5-piperidin-3-yl-phenoxy)-propionic acid ethyl ester d-tartaric acid salt

Participants

Reaction Steps

A 250 mL Parr bottle was charged with 0.27 g of 10% palladium on carbon (50% water) and covered with 20 mL ethanol. 3-[3-(1-ethoxycarbonyl-1-methyl-ethoxy)-4-methyl-phenyl]-piperidine-1-carboxylic acid benzyl ester (1.36 g, 3.09 mmol) was dissolved in 50 mL ethanol and added to the catalyst suspension. The reaction was hydrogenated at 50 psi for 2 h. The catalyst was filtered through a celite plug. The filter cake was washed with 150 mL ethanol and the filtrated concentrated under reduced pressure. The resultant oil was taken up in 20 mL hot ethanol to which was added D-tartaric acid (464 mg, 3.09 mmol) in 10 mL hot ethanol. The solution was allowed to stir 24 h at ambient temperature. The white crystalline precipitate was collected by filtration to yield 978 mg (69%) of 2-methyl-2-(2-methyl-5-piperidin-3-yl-phenoxy)-propionic acid ethyl ester D-tartaric acid salt as a white crystalline solid.

Provenance & Evidence