Hydrochloric Acid → Trimethylalanine

Participants

Reaction Conditions

Reaction Steps

Preparation of Me2Aib-Val-MeVal-Pro-Pro-NHBn×HCl 2-[N,N-Dimethylamino]-isobutyric acid (1.3 g, 10 mmol) and 5.5 g (10 mmol) H-Val-MeVal-Pro-Pro-NHBn×HCl were dissolved in 50 ml dry DMF. After cooling to 0° C., 1.6 g DEPCN (10 mmol) and 2.9 ml triethylamine were added to the reaction mixture. The resulting mixture was stirred at 0° C. for 2 h and at room temperature overnight. Ice water (50 mL) was then added, and the resulting mixture was extracted twice with diethyl ether. The ether extracts were washed with 1 N NaOH (1×) and aqueous NaCl (3×), then dried over sodium sulfate and evaporated to dryness under reduced pressure. The product was crystallized from 100 ml diethyl ether with HCl/ether, and recrystallized from acetone to give 1.2 g of the desired product, which was characterized by fast atom bombardment mass spectrometry ([M+H]+=627).

Provenance & Evidence