反应详情

2-Aminoterephtalic acid (0.500 g, 2.76 mmol) was dissolved in hot mixture of 30 mL of water and 10 mL of conc. HCl. The solution was cooled in ice/NaCl bath to 0° C. giving a suspension of HCl salt. The solution of sodium nitrite (0.230 g, 3.33 mmol in 10 mL of water) was added dropwise to the suspension of ammonium salt, maintaining the temperature below +5° C. The resulting solution was stirred for 20 min and added dropwise to the solution of 2,6-dichlorophenol (0.450 g, 2.76 mmol) in 80 mL of 2M KOH, cooled in ice/water bath. The reaction mixture was stirred for 2 hrs in ice/water bath and then acidified with 10% HCl to pH 2-3 and extracted with ethyl acetate (3×30 mL). The combined extract was washed with brine (30 mL), dried over Na2SO4 and evaporated. The crude product was purified by column chromatography on silica gel using 60:15:1 chloroform-methanol-acetic acid as an eluant to give phenol 6 as a orange solid (0.200 g, 20%).

1. customgiving
2. temperaturemaintaining the temperature below +5° C
3. extractionextracted with ethyl acetate (3×30 mL)
4. extractionThe combined extract
5. washwas washed with brine (30 mL)
6. dry with materialdried over Na2SO4
7. customevaporated
8. customThe crude product was purified by column chromatography on silica gel using 60:15:1 chloroform-methanol-acetic acid as an eluant