4-Methylmorpholine → HCID 86752893, compound

Participants

Reaction Steps

To a solution of Boc-2-naphthylalanine (2.68 g, 8.51 mmol, (Synthetech, Oregon) in THF (50 mL) at -10° C. were added 4-methylmorpholine (0.936 mL, 8.51 mmol) and isobutyl chloroformate (1.103 mL, 8.51 mmol). The mixture was stirred for 5 minutes, whereupon (S)-(E)-3-amino-5-phenyl-1-(2-naphthylsulfonyl)-1-pentene (3.30 g, 8.51 mmol) was added, followed by 4-methylmorpholine (0.936 mL, 8.51 mmol). The mixture was stirred for 45 minutes, diluted with ethyl acetate (100 mL), washed with 1M HCl (50 mL), saturated aqueous sodium bicarbonate (50 mL), and brine (50 mL), dried over MgSO4, filtered, and the solvent was removed under reduced pressure. The intermediate, (S)-(E)-3-(tert-butoxycarbonyl-2-naphthylalanyl)amino-5-phenyl-1-(2-naphthylsulfonyl)-1-pentene, was crystallized from a suitable mixture CH2 Cl2 /ether/hexane in 69% yield. The resulting material (3.83 g, 5.90 mmol) was dissolved in CH2Cl2 (5 mL) and was treated with HCl/dioxane (15 mL of a 4.0M solution. The mixture was stirred at room temperature for 1 hour. The solution was poured, with stirring, into ether (500 mL) and filtered. The solids were washed with ether (2×50 mL) and dried in vacuo to give the intermediate, (S)-(E)-3-(2-naphthylalanyl)-amino-5-phenyl-1-(2-naphthylsulfonyl)-1-pentene, 3.41 g, 99% yield.

Provenance & Evidence