Phosphorus oxychloride → 1-(4-bromophenyl)-5-chloro-3-(2-chloro-6-fluorophenyl)-1H-1,2,4-triazole

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Reaction Steps

To 2-(4-bromophenyl)-5-(2-chloro-6-fluorophenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (Intermediate-1, 0.100 g, 0.271 mmol) was added POCl3. The reaction mass was refluxed for 48 h. The reaction mass was quenched in water, basified with NaHCO3 and extracted with ethyl acetate and concentrated. The obtained crude product was purified with column chromatography on silica gel eluting with 0.5% EA:DCM to afford 0.110 g of the desired product. 1H NMR (300 MHz, DMSO d6): δ 7.44 (t, J=9.3 Hz, 1H), 7.53 (d, J=7.8 Hz, 1H), 7.60-7.68 (m, 1H), 7.72 (d, J=9.0 Hz, 2H), 7.85 (d, J=8.7 Hz, 2H). MS (m/z): 388.22 (M+H)+.

Provenance & Evidence