New synthetic approaches to 3-carhoxamides of 4-hydroxy-2<i>H</i>-1,2-benzothiazine 1,1-dioxide
作者:Joseph G. Lombardino、Harry A. Watson
DOI:10.1002/jhet.5570130226
日期:1976.4
Two new synthetic approaches to the title compounds are reported. In the first of these, starting with N-carbobenzyloxysarcosine, four synthetic steps are employed to finally assemble the C3C4 bond of the 1,2-benzothiazine ring. In the second approach, an enol ether is employed as a protecting group to allow formation of the 3-carboxamide function, which is followed by cleavage of the ether function
报道了两种新的标题化合物的合成方法。在这些中的第一个中,从N-羰基苄氧基肌氨酸开始,采用四个合成步骤以最终组装1,2-苯并噻嗪环的C 3 C 4键。在第二种方法中,将烯醇醚用作保护基以形成3-羧酰胺官能团,随后裂解醚官能团以得到所需的4-羟基-1,2-苯并噻嗪-3-羧酰胺1,1-二氧化物。