Triethylamine → (1S,5S)-1-Amino-7-methylene-4-oxo-3-[(1R)-1-phenylethyl]-3-azabicyclo[3.3.0]octane

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Reaction Steps

Triethylamine (0.489 ml, 3.50 mmol) and diphenylphosphoryl azide (0.491 ml, 2.28 mmol) were added to a solution of [(1S,5S)-7-methylene-4-oxo-3-[(1R)-1-phenylethyl]-3-azabicyclo[3.3.0]octan-1-yl]carboxylic acid (500 mg, 1.75 mmol) in toluene (8.75 ml) in a nitrogen atmosphere with stirring under ice-cooling. The mixture was stirred at room temperature for 30 minutes and then at 100° C. for 30 minutes. The reaction solution was concentrated under reduced pressure, and triethylamine was azeotropically removed with toluene (×3). 1,4-Dioxane (4.37 ml) and 6 mol/L hydrochloric acid (4.37 ml) were added to the resulting residue, and the mixture was stirred at 50° C. for one hour. The reaction solution was diluted with water (18.0 ml) and washed with diethyl ether (60 ml×2). The aqueous layer was made alkaline with a 1 mol/l sodium hydroxide solution, followed by extraction with chloroform (80 ml×1, 70 ml×1). The organic layer was washed with water (80 ml) and brine (80 ml) and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to give 238 mg of the title compound.

Provenance & Evidence