Tetrahydrofuran → Acetic acid 10-acetoxymethyl-anthracen-9-ylmethyl ester

Participants

Reaction Steps

Triethylamine (0.84 ml., 6.0 mmole) and dicyclohexylcarbodiimide (453 mg., 2.20 mmole) are added to mixture of N-[(1S, 2R)-1-(cyclohexylmethy)-2-hydroxy-2-[1-[(phenylmethoxy)methyl]-1H-imidazol-2-yl]ethyl]-N3 -[(phenylmethoxy)methyl]-L-histidinamide (1.47 g., 2.0 mmole) [prepared as set forth in Example 11 (e)], the product from part (c) (582 mg., 2.20 mmole), and 1-hydroxybenzotriazole hydrate (337 mg., 2.20 mmole) in tetrahydrofuran (8 ml.) at 0°. The resulting mixture is stirred overnight as it warms to 25°, after which it is filtered. The filtrate is diluted with ethyl acetate, washed with saturated sodium bicarbinate solution and brine, dried (MgSO4), and concentrated. The residue is flash chromatographed on silica gel (Merck) eluting with ethyl acetate:pyridine:acetic ecid:water (80:20:6:11) to give as the major product 1.48 g. of N-[(S)-2-cyclohexyl-1-[(R)-hydroxy[1-[(phenylmethoxy)methyl]-1H-imidazol-2-yl]methyl]ethyl]-N2 -[N-[[(1,1-dimethylethyl)amino]-carbonyl]-L-phenylalanyl]-N3 -[(phenylmethoxy)methyl]-L-histidinamide. [α]D =-3.5° (c=9, methanol).

Provenance & Evidence