1-Cyclohexyl-2-(furan-3-yl)-1H-benzimidazole-5-carboxylic acid → (2S)-3-(3-azido-4-hydroxy-phenyl)-2-[[1-cyclohexyl-2-(3-furyl)benzimidazole-5-carbonyl]amino]propanoic acid

Participants

Reaction Steps

To a solution of 3-amino-L-tyrosine.2HCl.H2O (2.50 g, 8.8 mmol) in 0.5 N HCl (28 mL) at 0° C., an aqueous solution of NaNO2 (0.724 g, 10.5 mmol, in 10 mL H2O) was added slowly. The reaction mixture was stirred for 10 min at 0° C., in the dark, and then a solution of NaN3 (1.43 g, 21.9 mmol, in 10 mL H2O) was added and stirring was continued for 1 h at 0° C. The white solid formed was filtered and dried to give (S)-2-amino-3-(3-azido-4-hydroxy-phenyl)-propionic acid (1.16 g) as of a beige solid. This amino acid was coupled to the carboxylic acid of example 2 in the usual manner to give the title compound of example 146 after purification by preparative C18 reversed-phase HPLC.

Provenance & Evidence