Ethylmorpholine → HCID 178501408, compound

Participants

Reaction Steps

A solution of N,N1 -dicyclohexylcarbodiimide (DCC, 13.6 g, 66 mmol) in distilled dimethylformamide (DMF, 15 ml) is added dropwise to a cold solution (0° to 5° C.) of Z-Pro-OH (15 g, 60 mmol) and 1-hydroxybenzotriazole (HOBt, 12.16 g, 120 mmol), in distilled DMF (40 ml). The mixture is stirred at 0°-5° C. for 2 hr. Thereafter, a solution of H-His-OMe.2HCl (14.56 g, 60 mmol) and N-ethylmorpholine (15.2 g, 16.89 ml, 132 mmol) in distilled DMF is added to the cold reaction mixture. The pH of the reaction mixture is adjusted to 8 and the reaction mixture stirred for 18 hr at 20°-22° C. The solid (N,N1 -dicyclohexylurea) is removed from the mixture by filtration. The filtrate is concentrated to dryness under reduced pressure. The residue is subjected to chromatography on silica gel (2400 g) using chloroform-methanolpyridine (89:10:1) as the eluant. The pure fractions are pooled and evaporated under reduced pressure to give 16.2 g of the title compound; NMR (CDCl3) δ 3.70 (s, 3H), 5.12 (s, 2H), 7.25 (s, 5H); amino acid analysis: His (1.00), Pro (0.97).

Provenance & Evidence