Addition-cyclization reactions of 3-bromo- and 3-chloro-2-methylpropenoylisothiocyanates with primary and secondary amines and alcohols have been studied. The formed addition products, thioureas, underwent cyclization of heating with ethanolic KOH or in dimethylformamide in the presence of lithium hydride. This method represents a new approach to 2-dialkyl(aryl)amino-5-methyl-4H-1,3-thiazin-4-ones. Addition reactions with alcohols afforded 3,4-dihydro-5-methyl-2,4-dioxo-2H-1,3-thiazine as the sole product. The structure of the synthesized compounds was confirmed by 1H NMR, 13C NMR, IR and mass spectroscopy.
研究了3-溴-和3-氯-2-甲基丙烯酰异硫氰酸酯与一级和二级胺以及醇的加成-环化反应。形成的加成产物,硫脲,在乙醇性KOH或在二甲基甲酰胺中存在锂氢化物的情况下加热后发生环化。这种方法代表了一种新的制备2-二烷基(芳基)氨基-5-甲基-4 H-1,3-噻嗪-4-酮的方法。与醇的加成反应仅产生3,4-二氢-5-甲基-2,4-二氧杂-2 H-1,3-噻嗪作为唯一产物。合成化合物的结构通过1H NMR,13C NMR,IR和质谱得到了确认。