HCID 53986256, compound → HCID 22818939, compound

Participants

Reaction Steps

A solution of 5.3 g (0.014 mole) of N-carbobenzyloxy-4-[(4-chlorophenyl)methylene]-L-proline in 150 ml of ethanol is treated with 0.45 g of platinum dioxide and shaken on a Parr hydrogenator at a starting pressure of 15 lbs. (bottle gauge). The uptake of hydrogen is carefully monitored and whenever the pressure falls to 5 lbs the bottle is replenished with hydrogen to 15 lbs. A noticeable slowing down of the rate of hydrogen uptake is observed after eight minutes and the hydrogenation is interrupted after a total of ten minutes (21.5 lbs of hydrogen). The catalyst is filtered off (celite bed under nitrogen atmosphere), washed well with ethanol, and the combined filtrates are evaporated, finally at 0.2 mm, to yield 4.6 g of N-carbobenzyloxy-cis-4-[(4-chlorophenyl)methyl]-L-proline as a colorless brittle foam.

Provenance & Evidence