Sodium Hydroxide → HCID 67332907, compound

Participants

Reaction Conditions

Reaction Steps

Methyl (2S)-4-(2-{[(benzyloxy)carbonyl]amino}ethyl)-2-methyl-3-oxo-2-phenyl-7-(trifluoro-methyl)-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (1.1117 g) was dissolved in 1,4-dioxane (20 ml), and thereto was added 4N-aqueous sodium hydroxide solution (20 ml), and the mixture was stirred at 50° C. for 6 hours. The mixture was cooled to room temperature, and concentrated under reduced pressure to remove 1,4-dioxane. The residue was diluted with water, and the pH value thereof was adjusted to pH 1 with 3N-hydrochloric acid. The precipitated white solid was collected by filtration to give (2S)-4-(2-{[(benzyloxy)carbonyl]amino}ethyl)-2-methyl-3-oxo-2-phenyl-7-(trifluoromethyl)-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylic acid (1.016 2 g). Thus obtained carboxylic acid (717.7 mg) was dissolved in DMF (6 ml), and thereto were added triethylamine (0.75 ml), dimethylaminopyridine (82.0 mg), tert-butyl (3R)-3-(isopropylamino)piperidine-1-carboxylate (1.3400 g), CIP reagent (1.1922 g), and the mixture was stirred at 60° C. under nitrogen atmosphere for 7 hours. To the mixture were additionally added triethylamine (0.57 ml) and CIP reagent (747.7 mg), and the mixture was further stirred at 60° C. for 4 hours. The reaction solution was cooled to room temperature, diluted with water, and extracted with ethyl acetate. The organic layer was washed with water and a saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, and concentrated under reduced pressure to give a crude product, which was purified by silica gel chromatography to give the title compound (588.4 mg).

Provenance & Evidence