反応 #5935

反応方程式

(R)-2-(4-Chlorophenyl)-4-[(S)-N-(2-naphthalenesulfonyl)prolyl]-3,4-dihydro-2H-1,4-benzothiazine

potassium hydroxide

→

(R)-(+)-2-(4-chlorophenyl)-3,4-dihydro-2H-1,4-benzothiazine

収率 58.7%

溶媒

ethanol water

反応条件

後処理

1. 1
   温度the mixture is refluxed for 30 minutes
2. 2
   抽出the mixture is extracted with ethyl acetate
3. 3
   洗浄The ethyl acetate layer is washed with water and saline
4. 4
   乾燥dried over sodium sulfate
5. 5
   workup.DISTILLATIONdistilled
6. 6
   その他to remove the solvent
7. 7
   その他The residue is purified by silica gel column chromatography (CHCl3)
8. 8
   その他recrystallized from ethyl acetate-hexane twice

実験手順

(R)-2-(4-Chlorophenyl)-4-[(S)-N-(2-naphthalenesulfonyl)prolyl]-3,4-dihydro-2H-1,4-benzothiazine (9.40 g, 0.017 mole) is suspended in ethanol-water (10:1, 188 ml), and thereto is added 86 % potassium hydroxide (11.2 g, 0.172 mole), and the mixture is refluxed for 30 minutes. 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 twice to give (R)-(+)-2-(4-chlorophenyl)-3,4-dihydro-2H-1,4-benzothiazine (2.61 g, 58%).

出典