Water → HCID 178484874, compound

Participants

Reaction Steps

23.1 g (0.03 mole) of N-benzyloxycarbonyl-N-methyl-D-phenylalanyl-L-prolyl-Nω -benzyloxycarbonyl-L-arginine-aldehyde (Example 1, Step 2) are dissolved in 150 ml of ethanol, 50 ml of deionized water and 48 ml of N sulfuric acid are added and the mixture is submitted to hydrogenolysis in the presence of 3 g of a 10 percent Pd/C catalyst. The progress of the hydrogenolysis is monitored by thin-layer chromatography in a developing solvent of ethyl acetate-pyridine-acetic acid-water-30:20:6:11 (Rf values of the starting material, intermediary and final product about 0.9, 0.7 and 0.4, respectively). After completed reaction the catalyst is filtered and washed three times with 30 ml of deionized water. The filtrate and washings are combined and concentrated to about 100 ml in a rotary evaporator. The aqueous residue is diluted to about 200 ml with deionized water and its pH is controlled. If it is not between 6.0 and 6.5, it is adjusted with 0.1N sulfuric acid or an ion-exchange resin in OH cycle (i.e. AG 1X8), then the solution is freeze-dried. Yield 12.4 g (75%).

Provenance & Evidence