Abstract
The reactions of 2- and 4-chloro or -hydroxy derivatives of pyridine and quinoline N-oxides with morpholine enamine of cyclohexanone in the presence of an acylating agent were examined. From N-oxides of 4-chloroe derivatives (I, II), 2-(4-chloro-2-pyridyl and -quinolyl) cyclohexanone (III, IV) were obtained in good yields. 2-Chloropyridine 1-oxide gave 2-(2-chloro-4-pyridyl cyclohexanone (X) as the main product accompanied by a few percent of the 6-pyridyl compound (IX)). Similarly 2-chloroquinoline 1-oxide (XII) yielded 2-(2-chloro-4-quinolyl) cyclohexanone (XIII) as a sole product, no dispalcement of 2-chloro atom being detectable. The reaction of 4-quinolinol 1-oxide (XV) led to the formation of 2-(4-hydroxy-3-quinolyl) cyclohexanone (XVI), accompanied by small amounts of by-products.
