Reacción #5937

Ecuación de reacción

(R)-3-(4-chlorophenyl)-1-[(S)-N-(2-naphthalenesulfonyl)prolyl]-2,3-dihydro-1H-naphtho[2,1-b][1,4]thiazine

potassium hydroxide

→

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

Rendimiento 63.1%

Disolventes

ethanol water

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturais refluxed under argon for one hour
2. 2
   Extracciónthe mixture is extracted with ethyl acetate
3. 3
   LavadoThe ethyl acetate layer is washed with water and saline
4. 4
   Secadodried over sodium sulfate
5. 5
   workup.DISTILLATIONdistilled
6. 6
   Otroto remove the solvent
7. 7
   OtroThe residue is purified by silica gel column chromatography (CHCl3)
8. 8
   Otrorecrystallized from ethyl acetate-hexane

Procedimiento

A mixture of (R)-3-(4-chlorophenyl)-1-[(S)-N-(2-naphthalenesulfonyl)prolyl]-2,3-dihydro-1H-naphtho[2,1-b][1,4]thiazine (11.50 g, 0.019 mole), 86 % potassium hydroxide (15.0 g, 0.227 mole) and ethanol-water (10:1, 230 ml) is refluxed under argon for one hour. The reaction mixture is poured into ice water and the mixture is extracted with ethyl acetate. The ethyl acetate layer is washed with water and saline, dried over sodium sulfate and distilled to remove the solvent. The residue is purified by silica gel column chromatography (CHCl3) and thereafter recrystallized from ethyl acetate-hexane to give (R)-(+)-3-(4-chlorophenyl)- 2,3-dihydro-1H-naphtho[2,1-b][1,4]thiazine (3.74 g, 63%). M.p. 205°-206° C.

Fuente