反応 #7182

反応方程式

potassium carbonate

2-aminothiophenol

chloroacetic acid

→

2-chloromethylbenzoxazole

2-chloromethylbenzothiazole

溶媒

water

—

polyphosphoric acid

反応条件

後処理

1. 1
   温度The reaction was then cooled
2. 2
   抽出The mixture was then extracted with ethyl acetate
3. 3
   乾燥the combined organic fractions were then dried over MgSO4
4. 4
   濃縮concentrated
5. 5
   その他The residue was then purified by column chromatography on silica gel (50% ethyl acetate in hexanes)

実験手順

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).

出典