A metal- and base-free domino protocol for the synthesis of 1,3-benzoselenazines, 1,3-benzothiazines and related scaffolds
作者:V. P. Rama Kishore Putta、Raghuram Gujjarappa、Ujjawal Tyagi、Prasad P. Pujar、Chandi C. Malakar
DOI:10.1039/c8ob03058h
日期:——
Efficient and operationally simple protocols have been demonstrated for the synthesis of the title compounds using easily available starting materials under mild conditions, giving a broad range of rarely reported molecules in excellent yields.
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。
Novel β-lactam condensed 3-thiaquinolines: an efficient synthesis and structural characterization
Quinoline analog 2-aryl-4H-3,1-benzothiazine derivatives 8–13, obtained by the condensation of o-aminobenzyl chloride 1 with substituted thiobenzamides 2–7, were transformed to azeto[2,1-a][3,1]benzothiazin-1-one derivatives 18–23a,b,c and 24d,e by reaction with the corresponding substituted acetyl chlorides 14–17 in the presence of triethylamine. The structures of the new molecules were determined
Synthesis and reactions of 4<i>H</i>-3,1-benzothiazines
作者:S. I. El-Desoky、E. M. Kandeel、A. H. Abd-El-Rahman、R. R. Schmidt
DOI:10.1002/jhet.5570360124
日期:1999.1
This study is directed towards the synthesis of the pyrrolo[1,2-α]indole skeleton which is the essential ring system of the active antitumor miomycins. To this end a number of fused heterocycles such as benzothiazines, benzoxazines, indoles and quinolines were synthesized. The structures of the new compounds were assigned by ir, 1H nmr and ms-data.
这项研究针对吡咯并[1,2-α]吲哚骨架的合成,该骨架是活性抗肿瘤霉素的必不可少的环系统。为此目的,合成了许多稠合的杂环,例如苯并噻嗪,苯并恶嗪,吲哚和喹啉。新化合物的结构由ir,1 H nmr和ms数据指定。
Gabriel; Posner, Chemische Berichte, 1894, vol. 27, p. 3519