Reacción #5927

Ecuación de reacción

potassium carbonate

hydrochloric acid

hydrochloric acid

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

sodium borohydride

→

3-(4-chlorophenyl)-2,3-dihydro-1H-naphtho[2,1-b][1,4]thiazine

Rendimiento 88.0%

Disolventes

methanol

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturathe mixture is refluxed for 2 hours
2. 2
   TemperaturaAfter cooling, to the mixture
3. 3
   Temperaturathe mixture is further refluxed for 4 hours
4. 4
   Extracciónextracted with ethyl acetate
5. 5
   LavadoThe ethyl acetate layer is washed
6. 6
   Otrodried
7. 7
   workup.DISTILLATIONdistilled
8. 8
   Otroto remove the solvent
9. 9
   OtroThe residue is recrystallized from tetrahydrofuran-n-hexane

Procedimiento

To a solution of 3-(4-chlorophenyl)-1H-naphtho[2,1-b][1,4]thiazin-2(3H)-one (38.45 g) and sodium borohydride (22.32 g) in tetrahydrofuran (1.0 liter) is added dropwise with stirring boron trifluoride etherate complex (100 ml) at room temperature, and the mixture is refluxed for 2 hours. After cooling, to the mixture are added methanol (200 ml), 10% hydrochloric acid (300 ml) and conc. hydrochloric acid (150 ml) in this order and the mixture is further refluxed for 4 hours. To the reaction mixture is added ice water and the mixture is made alkaline with potassium carbonate and extracted with ethyl acetate. The ethyl acetate layer is washed, dried and distilled to remove the solvent. The residue is recrystallized from tetrahydrofuran-n-hexane to give 3-(4-chlorophenyl)-2,3-dihydro-1H-naphtho[2,1-b][1,4]thiazine (32.3 g, yield 88%) as crystals.

Fuente