反应详情

The sulphonic acid (2a) was dissolved in an excess of thionyl chloride (30 mL), a catalytic amount of DMF (cat) was added, and the resulting mixture was stirred for 6 h at reflux. The solvent was evaporated and the residue dissolved in Et20 (40 mL). The ether solution was washed with 5% aqueous NaOH (3×40 mL) and water (6×40 mL), dried over anhydrous MgSO4, filtered, and concentrated in vacuo. After drying in high vacuum overnight, the pure product was obtained as a white solid. Yield 63%: 2.09 g, 7.44 mmol, (light yellow syrup). 1H-NMR (CDCl3): δ 7.44 (d, 3J=9.1 Hz, 2H, ArH), 7.38 (d, 3J=9.1 Hz, 2H, ArH), 7.19 (t, 1H, ArH), 7.12 (d, 3J=9.1 Hz, 2H, ArH), 6.98 (d, 3J=9.1 Hz, 2H, ArH)

1. temperatureat reflux
2. customThe solvent was evaporated
3. dissolutionthe residue dissolved in Et20 (40 mL)
4. washThe ether solution was washed with 5% aqueous NaOH (3×40 mL) and water (6×40 mL)
5. dry with materialdried over anhydrous MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customAfter drying in high vacuum overnight
9. customthe pure product was obtained as a white solid