Reaktion #5923

Reaktionsgleichung

4-bromobutyryl chloride

2-(4-chlorophenyl)-3,4-dihydro2H-1,4-benzothiazine

sodium hydrogen carbonate

→

4-(4-bromobutyryl)-2-(4-chlorophenyl)-3,4-dihyro-2H-1,4-benzothiazine

Ausbeute 93.2%

Lösungsmittel

ethyl acetate

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   WaschenThe ethyl acetate layer is washed
2. 2
   Sonstigedried
3. 3
   workup.DISTILLATIONdistilled
4. 4
   Sonstigeto remove the solvent
5. 5
   SonstigeThe residue is recrystallized from ethyl acetate-n-hexane

Vorschrift

To a mixture of 2-(4-chlorophenyl)-3,4-dihydro2H-1,4-benzothiazine (1.08 g), ethyl acetate (20 ml) and aqueous sodium hydrogen carbonate solution (20 ml) is added dropwise a solution of 4-bromobutyryl chloride (0.97 g) in ethyl acetate (5 ml) with stirring under ice cooling. The ethyl acetate layer is washed, dried and distilled to remove the solvent. The residue is recrystallized from ethyl acetate-n-hexane to give 4-(4-bromobutyryl)-2-(4-chlorophenyl)-3,4-dihyro-2H-1,4-benzothiazine (1.58 g, yield 93%).

Quelle