Triethylamine → 2-(2,6-difluorophenyl)-4-(4-chlorophenyl)-5,6-dihydro-4H-1,3-oxazine

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Reaction Steps

A mixture of 1.74 g (15.2 mmol) of methanesulfonyl chloride and 10 ml of tetrahydrofuran is added dropwise to a mixture of 4.5 g (13.8 mmol) of N-(2,6-difluorobenzoyl)-3-amino-3-(4-chlorophenyl)-1-propanol, 1.54 g (15.2 mmol) of triethylamine and 50 ml of tetrahydrofuran, while cooling with ice and stirring. The mixture is stirred at room temperature for 2 hours and filtered, and the filtrate is concentrated in vacuo. The residue is taken up in 50 ml of methanol, 2 g of potassium hydroxide are added and the mixture is stirred at 70° C. for 30 minutes. After customary working up, the crude product is purified by column chromatography on silica gel using the mobile phase n-hexane/ethyl acetate 8/2. 3.1 g (72.9%) of 2-(2,6-difluorophenyl)-4-(4-chlorophenyl)-5,6-dihydro-(4H)1,3-oxazine are obtained as a colorless oil.

Provenance & Evidence