Reacción #5924

Ecuación de reacción

methyl α-bromo-4-chlorophenylacetate

1-amino-2-naphthalenethiol

sodium borohydride

sodium acetate

→

3-(4-chlorophenyl)-1H-naphtho-[2,1-b][1,4]thiazin-2(3H)-one

Rendimiento 86.0%

Disolventes

ethanol

acetic acid

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.WAITthe mixture is sitrred at room temperature under argon overnight
2. 2
   Otrothe resulting precipitate is separated by filtration
3. 3
   Lavadowashed
4. 4
   Otrodried
5. 5
   Otrorecrystallized from tetrahydrofuran-n-hexane

Procedimiento

To a solution of 1-amino-2-naphthalenethiol (27.81 g) in ethanol (500 ml) is added sodium borohydride (11.35 g) at room temperature. The mixture is stirred for 20 minutes, and thereto is added dropwise acetic acid (200 ml) and is further added sodium acetate (24.6 g). To the mixture is further added dropwise methyl α-bromo-4-chlorophenylacetate (46.8 g), and the mixture is sitrred at room temperature under argon overnight. The reaction mixture is poured into ice water and the resulting precipitate is separated by filtration, washed, dried and recrystallized from tetrahydrofuran-n-hexane to give 3-(4-chlorophenyl)-1H-naphtho-[2,1-b][1,4]thiazin-2(3H)-one (44.45 g, yield 82.6%) as crystals.

Fuente