Pyridine → HCID 18474975, compound

Participants

Reaction Conditions

Reaction Steps

In 150 ml of toluene was dissolved 28.0 g (122 mmol) of N-(1-naphthyl) methyl -glycine methyl ester to obtain a toluene solution. To the resulting toluene solution was added an aqueous solution in which 12.9 g of anhydrous sodium carbonate had been dissolved in 200 ml of water. The mixture was cooled to 0° C. under stirring and 18.1 g (183 mmol) of a phosgene gas was blown to react these materials. After completion of the blowing, the mixture was reacted for 2 hours, and further stirred at room temperature for one hour. After completion of the reaction, the aqueous layer was separated from the resulting reaction mixture (1). The toluene layer was dried over anhydrous magnesium sulfate and filtered, and 24.7 g (244 mmol) of triethylamine was added to the filtrate and the mixture was heated to 120° C. for 12 hours. Then, 9.65 g (122 mmol) of pyridine was added to the mixture to effect reaction at 120° C. for 10 hours. After completion of the reaction, the resulting reaction mixture (2) was cooled to room temperature and precipitated amine hydrochloride was separated by filtration. The filtrate was washed with 100 ml of a saturated aqueous ammonium chloride solution and 100 ml of a saturated aqueous sodium chloride solution. The toluene layer was dried over anhydrous magnesium sulfate, followed by filtration, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by applying to silica gel column chromatography (eluent; n-hexane:ethyl acetate=4:1 (volume ratio)) and recrystallization was carried out from a n-hexane and ethyl acetate mixed solution to obtain 13.3 g (52.2 mmol) of 3-(1-naphthyl)methyl-5-methoxy-2(3H)-oxazolone as white crystals. (Yield based on N-(1-naphthyl)-methyl-glycine methyl ester=43%)

Provenance & Evidence