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A mixture of amide 3a, 9.5 g, 24.9 mmol) and P2O5 (44 g) in o-dichlorobenzene (150 mL) was refluxed for overnight. 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 (6.68 g, 80%). mp 111-112° C. 1H NMR (CDCl3) d 2.67 (s, 3 H, CH3), 7.00-7.05 (m, 1 H, aromatic), 7.26-7.52 (m, 6 H, aromatic), 7.65 (d, J=8.1 Hz, 1 H, aromatic), 7.88 (d, J=8.1 Hz, 1 H, aromatic). 13C NMR (CDCl3) d 24.05 (q, CH3), 97.82 (s, =CI--, aromatic), 118.26 (d, aromatic), 124.45 (s, aromatic), 125.98 (d, aromatic), 126.77 (d, aromatic), 127.70 (d, aromatic), 129.43 (d, aromatic), 129.79 (d, aromatic), 129.92 (d, aromatic), 136.73 (s, aromatic), 138.78 (d, aromatic), 143.74 (s, aromatic), 150.24 (s, aromatic), 161.34 (s, =CCH3 --, aromatic). Anal. Calcd for C16H12IN: C, 55.67; H, 3.50; N, 4.06. Found: C, 55.77; H, 3.51; N, 3.96.

1. temperaturewas refluxed for overnight
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