Hydrochloric Acid → Ac-D-Lys(Z)-D-Pro-D-Val-NH2

Participants

Reaction Conditions

Reaction Steps

In an inert thermostable reactor provided with a mechanical stirrer, 94.25 g of Ac-D-Lys(Z)-D-Pro-OH (XI) (224.7 mmol) are introduced followed by 470 ml of DMF. 32.58 g of HCl. H-D-Val-NH2 (V) (213.5 mmol, 0.95 eq) and 85.22 g of HBTU (1 eq) are then added. The medium is cooled down to 5° C., and 96.6 ml of ethyldiisopropylamine (2.5 eq) are added dropwise within 15 minutes. This is allowed to reach 0° C. again and after 1.30 to 2 hours, a strong crystallization could be observed. The reaction completion is CCM controlled. The reaction medium is then poured onto 2350 ml of AcOEt, stirred for 15 minutes, filtered and washed successively with 470 ml of AcOEt and 470 ml of diisopropyl ether. The derivate (XII) is vacuum dried at 25° C. This way, 107.2 g (92%) pf Ac-D-Lys(Z)-D-Pro-D-Val-NH2 are obtained.

Provenance & Evidence