Synthesis of Substituted α,β-Unsaturated Ketones, Pyrazoles, Isoxazoles and 2,4,6-Triarylpyrylium Chlorophosphates via β-Lithiation of Benzotriazolylvinyl Ethyl Ether
作者:Ashraf A. Abdel-Fattah
DOI:10.1055/s-2004-837293
日期:——
Quenching the β-lithiated benzotriazolylvinyl ethyl ether 2 with aldehydes, acid chlorides and chalcones provided the corresponding β-hydroxyalkyl derivatives 4a-f, β-keto vinyl ethers 7a,b, and Michael adducts 8a,b, respectively. The alkylated product 4 was converted into α,β-unsaturated ketones 5a-f upon treatment with bromine. β-Keto vinyl ethers 7a,b cyclocondensed with hydrazines to afford pyrazoles 9a-d, and with hydroxylamine hydrochloride to give isoxazoles 10a,b. Treatment of 8 with phosphorus pentachloride resulted in the formation of 2,4,6-triarylpyrylium chlorophosphates 12.
将β-锂化苯并三唑乙烯醚 2 与醛、酸氯化物和查尔酮反应,分别得到相应的β-羟基烷基衍生物 4a-f、β-酮乙烯醚 7a,b 和迈克尔加成物 8a,b。将烷基化产品 4 与溴反应处理后转化为α,β-不饱和酮 5a-f。β-酮乙烯醚 7a,b 与氢肼环缩合以生成吡唑 9a-d,与盐酸羟胺反应则生成异噁唑 10a,b。将 8 与五氯化磷处理,生成 2,4,6-三芳基吡啶铵氯磷酸盐 12。