Pyridine → 4-Chloro-2-(2,6-dichlorophenyl)thiazolo[5,4-c]pyridine

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Reaction Steps

A mixture of 2,6-dichloro-N-(2-chloro-3-fluoropyridin-4-yl)benzimidoyl chloride (400 mg, 1.15 mmol), thiourea (305 mg, 4.0 mmol) and pyridine (325 μL, 4.0 mmol) in anhydrous isopropanol (6 mL) was heated under reflux under nitrogen for 3.5 hours. Triethylamine (1 mL) was added and heating was continued for a further 2 hours. The mixture was cooled to ambient temperature and concentrated under reduced pressure. The resultant residue was partitioned between DCM (15 mL) and water (15 mL). The aqueous phase was extracted with DCM (2×10 mL), the combined organic extract was dried over MgSO4 and concentrated under reduced pressure. The residue was purified by silica gel flash chromatography (0-10% EtOAc in pentane) to give the title compound as a beige solid (270 mg, 74% yield). 1H NMR (400 MHz, CDCl3): δ 8.52 (d, J=5.6 Hz, 1H), 7.98 (d, J=5.6 Hz, 1H), 7.52-7.48 (m, 2H), 7.45 (dd, J=9.6, 6.2 Hz, 1H).

Provenance & Evidence