(2,4-Dichlorophenyl)hydrazine monohydrochloride → HCID 22171031, compound

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Reaction Steps

To a round-bottom flask was added 6-(3,4-dichloro-phenyl)-6-hydroxy-4-oxo-hex-5-enoic acid bis-lithium salt (9.48 g, 31.3 mmol, 1.0 equiv), 2,4-dichloro-phenyl hydrazine hydrochloride (6.66 g, 31.3 mmol, 1.0 equiv) and EtOH (250 mL) under nitrogen. The mixture was stirred at room temperature for 24 h. The solvent was removed, and the crude residue was partitioned between 5% HCl and diethyl ether (200 mL each). The layers were separated, and the aqueous layer was extracted with diethyl ether (2×100 mL). The combined organic layers were washed with water (100 mL) then brine (100 mL), dried (Na2SO4), and concentrated under reduced pressure. Purification by flash chromatography (25% ethyl acetate/dichloromethane) afforded the title intermediate (4.5 g, 33%). HPLC: Rt=3.04 (Method A). MS (ESI): mass calculated for C18H12Cl4N2O2, 427.97; m/z found, 429/431 [M+H]+. 1H NMR (500 MHz, DMSO-d6): 12.20 (br s, 1H), 7.82 (d, J=2.2 Hz, 1H), 7.68 (d, J=8.5 Hz, 1H), 7.61-7.59 (m, 2H), 7.50 (d, J=2.2 Hz, 1H), 7.05 (dd, J=8.2, 1.9 Hz, 1H), 6.73 (s, 3H), 2.88 (t, J=7.4 Hz, 2H), 2.64 (t, J=7.4 Hz, 2H).

Provenance & Evidence