Reacción #7182

Ecuación de reacción

potassium carbonate

2-aminothiophenol

chloroacetic acid

→

2-chloromethylbenzoxazole

2-chloromethylbenzothiazole

Disolventes

water

—

polyphosphoric acid

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe reaction was then cooled
2. 2
   ExtracciónThe mixture was then extracted with ethyl acetate
3. 3
   Secadothe combined organic fractions were then dried over MgSO4
4. 4
   Concentraciónconcentrated
5. 5
   OtroThe residue was then purified by column chromatography on silica gel (50% ethyl acetate in hexanes)

Procedimiento

Using literature procedures (Addison, A. W.; Nageswara Rao, T.; Wahlgren, C. G. J. Heterocyclic Chem. 1983, 20, 1481–1484) a substituted 2-aminophenol (or a 2-aminothiophenol (5 mmol)) was mixed with chloroacetic acid (940 mg, 10 mmol) in polyphosphoric acid (5 mL), and the viscous mixture was then heated to 120° C. for 3 hours. The reaction was then cooled, and diluted with water (˜20 mL) and then neutralized with potassium carbonate to pH˜7. The mixture was then extracted with ethyl acetate, and the combined organic fractions were then dried over MgSO4 and concentrated. The residue was then purified by column chromatography on silica gel (50% ethyl acetate in hexanes) to afford the desired 2-chloromethylbenzoxazole (or 2-chloromethylbenzothiazole).

Fuente