Reacción #59159

Ecuación de reacción

HCl

isoamyl nitrite

2-amino-4-methylbenzothiazole

→

2-chloro-4-methyl-1,3-benzothiazole

Rendimiento 71.0%

Disolventes

acetonitrile

—

tri(ethylene glycol)dimethyl ether

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGThe reaction mixture was stirred at rt for 10 minutes
2. 2
   Temperaturaheated at 50° C. for 2.5 h
3. 3
   TemperaturaThe reaction mixture was cooled to rt
4. 4
   ExtracciónThe solution was extracted with EtOAc
5. 5
   LavadoThe organic layer was washed with HCl (1.0 M), water, brine
6. 6
   Filtraciónfiltered
7. 7
   Concentraciónconcentrated in vacuo
8. 8
   OtroThe residue was purified by flash chromatography (Biotage Flash 40M)

Procedimiento

To a solution containing copper chloride (II) (1.96 g, 14.61 mmol) and tri(ethylene glycol) dimethyl ether (6 mL) in acetonitrile (100 mL) was added isoamyl nitrite (2.14 g, 18.27 mmol), and the reaction mixture was stirred at rt for 30 minutes. To this suspension was added dropwise a solution of 2-amino-4-methylbenzothiazole (2.0 g, 12.18 mmol) in tri(ethylene glycol)dimethyl ether (10 mL). The reaction mixture was stirred at rt for 10 minutes, and then 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, brine, filtered and concentrated in vacuo. The residue was purified by flash chromatography (Biotage Flash 40M) using 5% ethyl acetate in hexane to afford 2-chloro-4-methyl-1,3-benzothiazole (1.6 g, 71%). 1H NMR (400 MHz, CD2Cl2) δ 2.70 (s, 3H), 7.32 (m, 2H), 7.64 (m, 1H).

Fuente