반응 #59164

반응 방정식

HCl

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

isoamyl nitrite

→

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

수율 48.0%

용매

—

tri(ethylene glycol)dimethyl ether

acetonitrile

acetonitrile

반응 조건

후처리

1. 1
   workup.STIRRINGThe reaction mixture was stirred at rt for 10 minutes
2. 2
   온도heated at 50° C. for 2.5 h
3. 3
   온도The reaction mixture was cooled to rt
4. 4
   추출The solution was extracted with EtOAc
5. 5
   세척The organic layer was washed with HCl (1.0 M), water and brine
6. 6
   여과filtered
7. 7
   농축concentrated
8. 8
   기타The residue was purified by flash chromatography (Biotage Flash 40M)

실험 절차

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).

출처