1-Hydroxybenzotriazole → Rac.-n-[2-bromo-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoyl]-2-(dimethoxyphosphinyl)glycine methyl ester

Participants

Reaction Conditions

Reaction Steps

Diisopropylethylamine (1.81 g, 14 mmol) was added to a solution of rac.-2-(dimethoxyphosphinyl)glycine methyl ester (Example 125) freshly prepared from rac.-N-benzyloxycarbonyl)-2-(dimethoxyphosphinyl)glycine methyl ester (5.00 g, 15.1 mmol), O-(benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (5.20 g, 13.7 mmol), 1-hydroxybenzotriazole (1.85 g, 13.7 mmol) and 2-bromo-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoic acid (Example 79; 4.80 g, 13.7 mmol) in N,N-dimethylformamide (50 mL). After the reaction was stirred for 4 h at 25° C., the volatiles were removed in vacuo. A solution of the residue in ethyl acetate (200 mL) was washed with 1N hydrochloric acid solution (100 mL), saturated aqueous sodium bicarbonate solution (100 mL), water (100 mL) and brine (100 mL). The organic layer was dried over MgSO4, filtered, concentrated and the resulting residue was flash chromatographed over silica gel (ethyl acetate-3% methanol in ethyl acetate) to give rac.-N-[2-bromo-4-[[(3-hydroxybenzyl)amino]carbonyl]benzoyl]-2-(dimethoxyphosphinyl)glycine methyl ester (5.50 g, 76% yield) as a colorless foam.

Provenance & Evidence