Exceptional isolation of both imine and enamine desmotropes of 4,1-benzothiazepines
作者:Péter Csomós、Lajos Fodor、Antal Csámpai、Pál Sohár
DOI:10.1016/j.tet.2010.02.084
日期:2010.4
Surprisingly, the desmotropes obtained could be separated by column chromatography and proved to be unexpectedly stable in solution. Further comparative studies revealed the existence of only the enamine forms of regioisomeric 2-ethoxycarbonyl-3-aryl-4,5-dihydro-7,8-dimethoxy-1,4-benzothiazepine derivatives; in this case, no desmotropy occurred. The structures were proved by means of NMR and IR spectroscopy
不同取代的(R ∗)-3-乙氧基羰基-2-芳基-3,5-二氢-4,1-苯并噻氮ze和3-乙氧基羰基-2-芳基-1,5-二氢-4,1-苯并噻氮ze的向同质性为调查。通过(2 R ∗,2a S ∗)-2-氯-2a-芳基-2,2a-二氢-2 H,4 H-氮杂至[1,2-一种] [3,1]苯并噻嗪-1-酮与乙醇钠的乙醇溶液。分离了扩环反应的β-氨基酯中间体。出人意料的是,所获得的除胶剂可通过柱色谱法分离,并证明在溶液中出乎意料地稳定。进一步的比较研究表明,仅存在区域异构体2-乙氧基羰基-3-芳基-4,5-二氢-7,8-二甲氧基-1,4-苯并噻氮庚因衍生物的烯胺形式。在这种情况下,没有发生大同小异性。通过NMR和IR光谱证实了结构。