Pyridine → (2,4-Difluoro-phenyl)-(3-methoxy-phenyl)-methanone oxime

Participants

Reaction Steps

Combine (2,4-difluoro-phenyl)-(3-methoxy-phenyl)-methanone (51.2 g, 0.206 mol) and pyridine (293.4 g, 300 mL). Add hydroxylamine hydrochloride (21.7 g, 0.312 mol) and heat to 100° C., under a nitrogen atmosphere, for 4 hours. TLC (20% ethyl acetate in heptane) shows that the reaction is complete. Concentrate the reaction mixture and dry (vacuum at 50° C.). Distribute the material between ethyl acetate and water. Wash the organic layer with 10% HCl, saturated sodium chloride, dry (MgSO4) and concentrated to obtain the title compound as a white solid (53.66 g, 99% Yield). Use compound in a crude form or recrystallize from heptane and dry (P2O5). NMR and MS are consistent with the final, desired compound, which is a mixture of the Z-isomer (81%) and the E-isomer (19%). mp=122° C.-127° C.

Provenance & Evidence