Ammonium Hydroxide → Gln-Pro-Gly

Participants

Reaction Conditions

Reaction Steps

Z-Glp-Pro-Gly-OH (1 eq.) was dissolved under stirring in DMA at 25° C. and NH4OH 25% (6 eq.) was added in such way that the temperature did not rise above 30° C. The mixture was stirred for at least 4 h at 25° C. The solution was concentrated under vacuum till the pH was ≦3. The concentrate was diluted with a NaCl aqueous solution and the pH was adjusted to 2.5 with a solution of KHSO4. The resulting aqueous solution was washed twice with IPE and then extracted three times with n-BuOH at 25° C. The organic layers were combined and washed with water. The resulting organic solution was concentrated under reduced pressure. The concentrated solution was diluted with ethanol and water at 20° C. and Pd/C (0.02 eq.) was added to the peptide solution. The solution was stirred at 20° C. followed by the introduction of hydrogen under pressure (0.3 bar). The solution was stirred for at least 2 hours and the completion of the reaction was checked by HPLC. The solution was filtered to remove the catalyst and, after one washing with demineralised water, the pH of the solution was adjusted to 6.0<pH<6.5 with an aqueous solution of NaHCO3. The free tripeptide was then precipitated by addition of ethanol. The solution was left to mature at 25° C. for 3 hours. The solid was filtered and washed with ethanol. After drying under vacuum, 60% of H-Gln-Pro-Gly-OH was recovered.

Provenance & Evidence