反应详情

温度

125 °C

Sulfoacetic acid (52 g, 371 mM) and EtOH (500 mL) were heated under reflux for 20 hours. The reaction mixture was cooled, and the excess ethanol was removed under vacuum to give 2 (see Chart I). A mixture of 2 (16.82 g, 100 mM) and POCl3 (30.67 g, 200 mM) was heated at 125° C. for 5 hours. The mixture was cooled and filtered, and excess POCl3 was removed to give 3 (see Chart I). Compound 3 (8.18 g, 43.83 mM) was added dropwise with stirring to a solution of 2,6-diisopropylaniline (15.54 g, 87.66 mM) in 50 mL CH2Cl2 maintained at 0° C. The mixture was stirred at room temperature for an additional 18 hours. The solvent was removed and the residue was redissolved in 100 mL ethyl acetate and washed with 1 N HCl and brine. The ethyl acetate was evaporated and the pure compound was isolated by chromatography over silica gel (EtOAc/hexane, 1:4 as eluant) as a white powder, 7.0 g (~50%), mp 114°-116° C.

1. temperatureunder reflux for 20 hours
2. temperatureThe reaction mixture was cooled
3. customthe excess ethanol was removed under vacuum
4. customto give 2 (see Chart I)
5. temperatureThe mixture was cooled
6. filtrationfiltered
7. customexcess POCl3 was removed
8. customto give 3 (see Chart I)
9. temperaturemaintained at 0° C
10. customThe solvent was removed
11. dissolutionthe residue was redissolved in 100 mL ethyl acetate
12. washwashed with 1 N HCl and brine
13. customThe ethyl acetate was evaporated
14. customthe pure compound was isolated by chromatography over silica gel (EtOAc/hexane, 1:4 as eluant) as a white powder, 7.0 g (~50%), mp 114°-116° C.