Reacción #5939

Ecuación de reacción

2-amino-5-chlorothiophenol

potassium hydroxide

ethanol

→

7-chloro-2-(4-chlorophenyl)-3-oxo-3,4-dihydro-2H-1,4-benzothiazine

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.DISTILLATIONthe mixture is distilled
2. 2
   Otroto remove ethanol
3. 3
   workup.ADDITIONis added methyl ° -bromo-4-chlorophenylacetate (7.38 g)
4. 4
   Temperaturathe mixture is refluxed overnight
5. 5
   ConcentraciónThe reaction mixture is concentrated
6. 6
   Otrothe resulting precipitate is separated by filtration
7. 7
   Lavadowashed
8. 8
   Otrodried
9. 9
   Otrorecrystallized from tetrahydrofuran-n-hexane

Procedimiento

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 ° -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.

Fuente