摘要 |
An improved method of preparing 3-(4-pyridinyl)-2-cyclohexen-1-one oxime from ethyl 5-oxo-2-[(4-pyridinyl)-carbonyl]hexanoate is a one pot sequence which comprises first heating ethyl 5-oxo-2-[(4-pyridinyl)carbonyl]hexanoate with excess sulfuric acid, neutralizing the excess acid, extracting the resulting 3-(4-pyridinyl)-2-cyclohexen-1-one with isopropyl alcohol, draining off the heavier aqueous layer, adding hydroxylamine hydrochloride to the isopropyl alcohol solution of said 2-cyclohexen-1-one, stirring the mixture at reflux, basifying the mixture and evaporating it to dryness, and isolating 3-(4-pyridinyl)-2-cyclohexen-1-one oxime from the residue. The oxime is an intermediate for preparing 3-(4-pyridinyl)aniline, in turn, an intermediate for preparing rosoxacin, an antibacterial agent. |