Реакция #8581

Уравнение реакции

(3S)-7,8-difluoro-3-methyl-3,4-dihydro-2H-[1,4]benzoxazine

diethyl ethoxymethylenemalonate

→

title compound

Diethyl [(3S)-7,8-difluoro-3-methyl-2,3-dihydro-4H-[1,4]benzoxazin-4-yl]methylenemalonate

Растворители

toluene

Условия реакции

Обработка

1. 1
   workup.WAITat 140° C. under reduced pressure for 30 minutes

Методика

1.20 g (99.8% ee) of (3S)-7,8-difluoro-3-methyl-3,4-dihydro-2H-[1,4]benzoxazine was dissolved in toluene (0.5 ml). After adding diethyl ethoxymethylenemalonate (1.92 g), the mixture was stirred at 120 for 30 minutes and then at 140° C. under reduced pressure for 30 minutes. The residue was subjected to silica gel column chromatography. Thus, 2.19 g (99.8% ee) of the title compound was obtained as a yellow oily product. The physical constants of the obtained compounds was identical with those described in Japanese Patent No. 2,769,174.

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