Triethylamine → HCID 86665014, compound

Participants

Reaction Steps

Under nitrogen atmosphere, the mixture was cooled with ice-bath, and to a solution of the obtained 4-[2-(dibenzylamino)ethyl]-2,7-dimethyl-6-{[(3R)-1-{[(2-methyl-2-propanyl)oxy]carbonyl}-3-piperidinyl](2-propanyl)carbamoyl}-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylic acid (27.2 g) in tetrahydrofuran (75 ml) were added triethylamine (5.8 g) and chloroformic acid isobutyl ester (6.2 g), and the mixture was stirred for one hour. The precipitated salt was filtered, and the filtrate was added dropwise into a suspension of sodium borohydride (2.9 g) in tetrahydrofuran-ethanol (50 ml-50 ml) under ice-cooling. The mixture was stirred for one hour, and thereto was added a saturated aqueous ammonium chloride solution, and the mixture was extracted with ethyl acetate. The organic layer was washed with a saturated aqueous sodium chloride solution, and dried over sodium sulfate. The sodium sulfate was removed by filtration, and the filtrate was concentrated under reduced pressure. The obtained residue was purified by silica gel chromatography to give 2-methyl-2-propanyl (3R)-3-[({4-[2-(dibenzylamino)ethyl]-2-(hydroxymethyl)-2,7-dimethyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-6-yl}carbonyl)(2-propanyl)amino]-1-piperidinecarboxylate (22.5 g).

Provenance & Evidence