Condensed heteroaromatic ring systems. XIX. Synthesis and reactions of 5-(tributylstannyl)isoxazoles

Article abstract of DOI:10.1016/S0040-4020(01)87123-4

3-Substituted 5-(tributylstannyl)isoxazoles were newly synthesized by the 1,3-dipolar cyctoadditton of nitrile oxides to tributylethynylstannane. The iodination and the palladium-catalyzed benzoylation of 5-(tributylstannyl)-3-methylisoxazolegave 5-iodo-3-methylisoxazole and 3-methyl-5-isoxazolyl phenyl ketone in satisfactory yields, respectively. The palladium-catalyzed cross-coupling reaction of the stannylisoxazole with 2-bromonitrobenzene followed by the catalytic hydrogenation over Raney nickel resulted in the formation of 2-methyll-4(1H)-quinolinone in 57% overall yield.