反应详情

温度

80 °C

4-Phenoxyaniline (30 g, 162 mmol) was added in portions to a stirred solution of 98% w/v sulphuric acid (93 ml) in water (480 ml). The mixture was heated at 80° C. for 30 minutes and then cooled to 0°-5° C. A solution of sodium nitrite (13.5 g, 196 mmol) in water (60 ml) was added dropwise and the mixture was stirred for 45 minutes at 0° C. The excess nitrous acid was destroyed with sulphamic acid. The solution was added to a stirred mixture of 2-mercaptoacetic acid (14.7 ml, 211 mmol), basic copper carbonate (10.8 g, 49 mmol) and acetone (180 ml) at 0° C. The mixture was warmed to ambient temperature. After 1 hour ethyl acetate (200 ml) was added and the insoluble material was removed by filtration. The filtrate was extracted with ethyl acetate. The combined extracts were then extracted with a saturated solution of sodium hydrogen carbonate. The combined aqueous extracts were acidified to pH 2 by the addition of 2M hydrochloric acid and extracted with ethyl acetate. The combined extracts were washed with brine and dried (MgSO4). The solvent was removed by evaporation to give 4-phenoxyphenylthioacetic acid as an oil (12.3 g) having a satisfactory NMR spectrum (200 MHz, CDCl3); 3.61 (s,2H), 6.93-7.46 (m,9 aromatic H), after purification by flash chromatography on silica (Merck Kieselgel Art 9385) using ethyl acetate/dichloromethane (1:1 v/v).

1. temperaturecooled to 0°-5° C
2. customThe excess nitrous acid was destroyed with sulphamic acid
3. temperatureThe mixture was warmed to ambient temperature
4. customthe insoluble material was removed by filtration
5. extractionThe filtrate was extracted with ethyl acetate
6. extractionThe combined extracts were then extracted with a saturated solution of sodium hydrogen carbonate
7. additionThe combined aqueous extracts were acidified to pH 2 by the addition of 2M hydrochloric acid
8. extractionextracted with ethyl acetate
9. washThe combined extracts were washed with brine
10. dry with materialdried (MgSO4)
11. customThe solvent was removed by evaporation