Preparation and Reactions of<i>N</i>-Alkyl(Aryl),<i>N</i>-Isothiocyanatomethyl Carboxamides. Synthesis of 1,3,5-Thiadiazepin-6-ones
作者:András Vass、Gábor Szalontai
DOI:10.1055/s-1986-31789
日期:——
N-Alkyl(aryl),N-isothiocyanato carboxamides 3 are prepared by the reaction of the corresponding 2-chloroacetamides 1 with potassium thiocyanate. In the case of N-aryl substitution the intermediate thiocyanates 2 could be isolated. These thiocyanates isomerize to isothiocyanates 3 at different rates depending on aryl substituents, temperature and solvents. The reaction between 3k and a nucleophilic agent (e.g. methanol, isopropylthiol, sodium hydrogensulfide, or ethyl malonate) results in the corresponding 1,3,5-thiadiazepin-6-ones, 5 by ring closure.
N-烷基(芳基)、N-异硫氰酸酯羧酰胺 3 是通过对应的 2-氯乙酰胺 1 与硫氰酸钾反应制备而成。在 N-芳基取代的情况下,中间体硫氰酸酯 2 可以被分离。这些硫氰酸酯以不同的速率异构化为异硫氰酸酯 3,速率取决于芳基取代基、温度和溶剂。3k 与亲核试剂(如甲醇、异丙基硫醇、氢硫酸钠或乙基马来酸酯)的反应导致通过环闭合生成相应的 1,3,5-噻二嗪-6-酮 5。