反応 #59164

反応方程式

HCl

5,7-difluoro-1,3-benzothiazol-2-amine

isoamyl nitrite

→

2-chloro-5,7-difluoro-1,3-benzothiazole

収率 48.0%

溶媒

—

tri(ethylene glycol)dimethyl ether

acetonitrile

acetonitrile

反応条件

後処理

1. 1
   workup.STIRRINGThe reaction mixture was stirred at rt for 10 minutes
2. 2
   温度heated at 50° C. for 2.5 h
3. 3
   温度The reaction mixture was cooled to rt
4. 4
   抽出The solution was extracted with EtOAc
5. 5
   洗浄The organic layer was washed with HCl (1.0 M), water and brine
6. 6
   ろ過filtered
7. 7
   濃縮concentrated
8. 8
   その他The residue was purified by flash chromatography (Biotage Flash 40M)

実験手順

To a solution containing copper chloride (II) (0.89 g, 6.64 mmol) and tri(ethylene glycol)dimethyl ether (6 mL) in acetonitrile (60 mL) was added isoamyl nitrite (0.97 g, 8.30 mmol) and the reaction mixture was stirred at rt for 30 minutes. To this suspension was added dropwise a solution of 5,7-difluoro-1,3-benzothiazol-2-amine (1.03 g, 5.53 mmol) in tri(ethylene glycol)dimethyl ether (20 mL) and acetonitrile (30 mL). The reaction mixture was stirred at rt for 10 minutes and heated at 50° C. for 2.5 h. The reaction mixture was cooled to rt, and then poured cautiously into cold aqueous 6 M HCl (400 mL). The solution was extracted with EtOAc. The organic layer was washed with HCl (1.0 M), water and brine, filtered, and concentrated. The residue was purified by flash chromatography (Biotage Flash 40M) using 5% ethyl acetate in hexane to afford 2-chloro-5,7-difluoro-1,3-benzothiazole (0.55 g, 48%). 1H NMR (400 MHz, CD2Cl2) 7.02 (m, 1H), 7.52 (m, 1H).

出典