methyl N-[(2R)-1-(methoxyamino)-1-oxo-3-phenylpropan-2-yl]carbamate

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A suspension of (R)-N-methoxy-2-(methoxycarbonylamino)-3-phenylpropanamide (III, EXAMPLE 2, 11.25 g, 44.6 mmol) in dichloromethane (170 ml) is cooled in an ice bath and trifluoroacetic acid (9.25 ml, 13.7 g, 0.120 mol) is added. Bis(trifluoroacetoxy)iodobenzene (19.78 g, 0.046 mol) is added portion wise over 10 min at 0°, and the mixture is stirred at this temperature for one hour. The mixture is washed with sodium carbonate mixture (10%) and dried over magnesium sulfate. The solvent is removed under reduced pressure to give a concentrate. Purification by flash chromatography (230-400 mesh silica gel, 40-50% ethyl acetate/hexane) gives the desired product. An analytical sample is crystallized from ethyl acetate/hexane to give the title compound, mp=117-119°; NMR (CDCl3) 2.85, 3.44, 3.72, 3.93, 4.42, 5.82, 7.09, 7.33 and 7.22 δ; IR (mineral oil) 1722 and 1703 cm−1; [a]25D=+34.20 (CH3OH, c=0.927). is cooled in an ice bath The mixture is washed with sodium carbonate mixture (10%) dried over magnesium sulfate The solvent is removed under reduced pressure to give a concentrate Purification by flash chromatography (230-400 mesh silica gel, 40-50% ethyl acetate/hexane)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of sodium carbonate (10.20 g, 96.2 mmol) in water (170 ml) is added to a mixture of (R)-2-(methoxycarbonylamino)-3-phenylpropanoic acid (II, EXAMPLE 1, ˜0.148 mol crude) in methylene chloride. Methoxylamine hydrochloride (14.2 g, 0.170 mol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) (31.21 g, 0.163 mol) are added, and the mixture is stirred at 20-25° for 22 hours. The mixture is diluted with tetrahydrofuran (to dissolve the precipitate) and the layers are separated. The aqueous layer is extracted with 1:1 tetrahydrofuran/ether, and the combined organic extracts are washed with hydrochloric acid (10%) and saturated sodium bicarbonate solution. The mixture is dried over magnesium sulfate, filtered and the solvent removed under reduced pressure. Crystallization from ethyl acetate gives the title compound, mp=154-155°; NMR (CDCl3) 3.05, 3.58, 3.61, 4.34, 5.66, 7.15-7.31 and 9.44 δ; IR (mineral oil) 1694 and 1668 cm−1; [a]25D=+5.2° (CH3OH, c=1.045). to dissolve the precipitate) and the layers are separated The aqueous layer is extracted with 1:1 tetrahydrofuran/ether the combined organic extracts are washed with hydrochloric acid (10%) and saturated sodium bicarbonate solution The mixture is dried over magnesium sulfate filtered the solvent removed under reduced pressure Crystallization from ethyl acetate