Imidazole → Benzyl (4-{[tert-butyl(dimethyl)silyl]oxy}-2-{[methoxy(methyl)amino]carbonyl}phenyl)carbamate

Participants

Reaction Steps

To a solution of 2-{[(benzyloxy)carbonyl]amino}-5-hydroxybenzoic acid (92 g, 0.32 mol) and N,O-dimethylhydroxyamine hydrochloride (38 g, 0.38 mol) in N,N-dimethylformamide (500 ml) was added triethylamine (53 ml, 0.40 mol), and the mixture was stirred at room temperature for 10 min. To the reaction mixture was added 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (73 g, 0.38 mol), and the mixture was stirred at room temperature for 6 hrs. The reaction mixture was poured into water, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was dissolved in N,N-dimethylformamide (500 ml), and tert-butyl(dimethyl)silyl chloride (48 g, 0.32 mol) and imidazole (21 g, 0.32 mol) were added. The mixture was stirred at room temperature for 6 hrs., poured into water and extracted with ethyl acetate. The extract was washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was evaporated and the residue was purified by silica gel column chromatography to give benzyl (4-{[tert-butyl(dimethyl)silyl]oxy}-2-{[methoxy(methyl)amino]carbonyl}phenyl)carbamate (91 g, yield 64%).

Provenance & Evidence