反应详情

To a solution of 2-amino-5-chlorothiophenol (4.49 g) in ethanol (30 ml) is added 96% potassium hydroxide (1.63 g), and the mixture is distilled to remove ethanol. The resulting solid material is suspended in toluene (70 ml) and thereto is added methyl α-bromo-4-chlorophenylacetate (7.38 g), and the mixture is refluxed overnight. The reaction mixture is concentrated, and the resulting precipitate is separated by filtration, washed, dried, and then recrystallized from tetrahydrofuran-n-hexane to give 7-chloro-2-(4-chlorophenyl)-3-oxo-3,4-dihydro-2H-1,4-benzothiazine (6.58 g) as crystals. M.p. 230°-233.5° C.

1. distillationthe mixture is distilled
2. customto remove ethanol
3. additionis added methyl α-bromo-4-chlorophenylacetate (7.38 g)
4. temperaturethe mixture is refluxed overnight
5. concentrationThe reaction mixture is concentrated
6. customthe resulting precipitate is separated by filtration
7. washwashed
8. customdried
9. customrecrystallized from tetrahydrofuran-n-hexane