反应详情

A mixture of amide 3b, 11.54 g, 30.3 mmol) and P2O5 (43 g) in o-dichlorobenzene (150 mL) was refluxed for 20 h. After it was cooled to room temperature, it was cooled to 0° C. by application of an external ice-water bath. To this cooled mixture was cautiously added 300 mL of H2O. After the vigorous reaction had subsided, the dark solution was washed with toluene (2×50 mL). The aqueous layer was cooled to 0° C. and made to pH >11 with 50% aqueous NaOH. The resulting mixture was extracted with toluene (4×50 mL). The organic layers were dried (MgSO4), filtered. The filtrate was concentrated in vacuo. The residue was recrystallized from benzene, thereby affording a white solid (6.5 g, 62%) mp 77-78° C. 1H NMR (CDCl3) d 2.72 (s, 3 H, CH3), 7.23 (t, J=7.8 Hz, 1 H, aromatic), 7.40-7.52 (m, 2 H, aromatic), 7.57-7.66 (m, 2 H, aromatic), 7.71-7.85 (m, 2 H, aromatic), 7.92 (d, J=8.7 Hz, 1 H, aromatic), 8.02 (s, 1 H, aromatic). 13C NMR (CDCl3) d 24.31 (q, CH3), 94.31 (s, =CI--, aromatic), 118.36 (d, aromatic), 126.39 (d, 2C, aromatic), 126.92 (d, aromatic), 129.08 (d, aromatic), 129.83 (d, aromatic), 129.99 (d, aromatic), 137.34 (d, aromatic), 137.47 (s, aromatic), 138.53 (d, aromatic), 141.70 (s, aromatic), 150.80 (s, aromatic), 158.36 (s, =CCH3 --, aromatic). Anal. Calcd for C16H12IN: C, 55.67; H, 3.50; N, 4.06. Found: C, 55.53; H, 3.56; N, 4.05.

1. temperaturewas refluxed for 20 h
2. temperatureit was cooled to 0° C. by application of an external ice-water bath
3. customAfter the vigorous reaction
4. washthe dark solution was washed with toluene (2×50 mL)
5. temperatureThe aqueous layer was cooled to 0° C.
6. extractionThe resulting mixture was extracted with toluene (4×50 mL)
7. dry with materialThe organic layers were dried (MgSO4)
8. filtrationfiltered
9. concentrationThe filtrate was concentrated in vacuo
10. customThe residue was recrystallized from benzene