Ammonia → Ethyl acetate hexane

Participants

Reaction Conditions

Reaction Steps

Boc-Nalψ[CH2S]Ala-NH2. Pseudopeptide Boc-Nalψ[CH2S]Ala-OH (1.33 g; 3.4 mmol) was dissolved in THF (25 ml) and the solution was cooled to -30° C. Et3N (0.48 ml; 3.4 mmol) was added, followed by isobutyl chloroformate (0.46 ml; 3.5 mmol). After 15 min an excess of NH3 in CHCl3 was added and the reaction was stirred for 30 min at -30° C. and at room temperature for 3 h. The solvent was removed in vacuo and the residue was dissolved in AcOEt (250 ml). The organic solution was washed with H2O (1×50 ml), NaHCO3 5% (2×50 ml), H2O (1×50 ml), 0.5M citric acid (2×50 ml) and saturated NaCl, then was dried over Na2SO4 and filtered. After evaporation in vacuo of AcOEt, the residue was crystallized from AcOEt/hexane (1.2 g; 90% yield).

Provenance & Evidence