Department of Chemistry, Faculty of Science, Cairo University, Egypt.
Molecules. 2011 May 31;16(6):4549-59. doi: 10.3390/molecules16064549.
3-Amino-3-thioxopropanamide (1) reacted with ethyl acetoacetate to form 6-hydroxy-4-methyl-2-thioxo-2,3-dihydropyridine-3-carboxamide (2), which reacted with α-haloketones 3 to produce 2,3-disubstituted-8-hydroxy-6-methyl-2H,5H-pyrido[3,2-f]-[1,4]thiazepin-5-ones 4a-c. Benzoylation of 4c led to the formation of the dibenzoate derivative 9. Compounds 4a-c could be prepared stepwise through the formation of S-alkylated derivatives 10a-c. Compounds 2, 4a-c, 9 and 10a-c were prepared using microwave as a source of heat, and gave better yields in shorter times than those achieved by traditional methods. Coupling of 4a-c with arenediazonium chlorides proceeded unusually to give the 6-hydroxy-4-methyl-2-(arylazo)thieno[2,3-b]pyridin-3(2H)-one ring contraction products 14. Structures of the newly synthesized compounds were proven by spectral and chemical methods.
3-氨基-3-硫代丙酰胺（1）与乙酰乙酸乙酯反应生成 6-羟基-4-甲基-2-硫代-2,3-二氢吡啶-3-甲酰胺（2），2,3-二取代-8-羟基-6-甲基-2H,5H-吡啶并[3,2-f]-[1,4]噻嗪-5-酮 4a-c 是由 2 与α-卤代酮 3 反应得到的。4c 的苯甲酰化导致形成二苯甲酸盐衍生物 9。化合物 4a-c 可以通过形成 S-烷基化衍生物 10a-c 逐步制备。化合物 2、4a-c、9 和 10a-c 是使用微波作为热源制备的，与传统方法相比，它们在更短的时间内获得了更好的产率。4a-c 与芳基重氮盐的偶联异常进行，得到 6-羟基-4-甲基-2-（芳基偶氮）噻吩并[2,3-b]吡啶-3（2H）-酮环收缩产物 14。新合成化合物的结构通过光谱和化学方法得到证明。
