Synthesis and anticonvulsant activity of new 6-methyl-1-substituted-4,6-diazaspiro[2.4]heptane-5,7-diones
摘要:
In the present study on the development of new anticonvulsants, twenty new 6-methyl-1-substituted-4,6-diazaspiro[2.4]heptane-5,7-diones were synthesized and tested for anticonvulsant activity using the maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) screens. Their neurotoxicity was determined by the rotorod test. In this series, all of the alkyl- and aryl-substituted 5,5-cyclo-propanespirohydantoins showed more or less protection against MES and/or scPTZ models. The most active of the series was 6-methyl-1-(4-(methylsulfonyl)phenyl)-4,6-diazaspiro[2.4]heptane-5,7-dione (6t), which showed a MES ED50 value of 12.5 mg/kg in mice. The median toxic dose (TD50) was 310 mg/kg, providing compound 6t with a protection index (PI = TD50/ED50) of 24.8 in the MES test which is better than phenytoin. (C) 2010 Elsevier Masson SAS. All rights reserved.
Accessing Dihydro-1,2-oxazine via Cloke–Wilson-Type Annulation of Cyclopropyl Carbonyls: Application toward the Diastereoselective Synthesis of Pyrrolo[1,2-<i>b</i>][1,2]oxazine
作者:Pankaj Kumar、Rakesh Kumar、Prabal Banerjee
DOI:10.1021/acs.joc.0c00531
日期:2020.5.15
A convenient additive-free synthesis of dihydro-4H-1,2-oxazines via a Cloke-Wilson-type ring expansion of the aryl-substituted cyclopropane carbaldehydes with the hydroxylamine salt is introduced. Comparatively less active cyclopropyl ketones also follow a similar protocol if supplemented by catalytic p-toluene sulfonic acid monohydrate. The transformation is performed in an open-to-air flask as it
access optically active cycloheptenes and [n,5,0]carbobicycles. Mechanisic study reveals that the reaction involves a stepwise pathway, which undergoes an unusual ringopening of five-membered [3 + 2] intermediate and sequential intramolecular cyclization to afford the thermodynamically stable [4 + 3] annulation product.
Lewis Acid-Catalyzed [3+2] Cycloaddition of Donor-Acceptor Cyclopropanes and Enamines: Enantioselective Synthesis of Nitrogen-Functionalized Cyclopentane Derivatives
作者:Kamal Verma、Prabal Banerjee
DOI:10.1002/adsc.201600221
日期:2016.6.30
efficient method for the synthesis of nitrogen‐functionalized cyclopentane derivatives via [3+2] cycloaddition of enamines with donor‐acceptor cyclopropanes in the presence of catalytic amounts of various Lewisacids at room temperature has been developed; furthermore, the corresponding β‐amino acid was synthesized by monodecarboxylation and hydrogenolysis. An enantioenriched synthesis of nitrogen‐functionalized
bisoxazoline (BOX)/CuII catalyst. This reaction works well with cyclic enol silyl ethers of different sizes, and can be extended to dienol and benzene‐fused substrates, thus providing an effective and general access to a range of 3a‐hydroxy [n.3.0]carbobicycles which are found as a core structure in many natural products. TBDPS=tert‐butyldiphenylsilyl.
新的保险丝:使用新的双恶唑啉(BOX)/ Cu II催化剂实现了标题反应。该反应适用于不同大小的环状烯醇甲硅烷基醚,并且可以扩展至二烯醇和苯稠合的底物,从而提供有效且普遍的接触范围为3a-羟基[ n。3.0]碳双环被发现是许多天然产物的核心结构。TBDPS =叔丁基二苯基甲硅烷基。
Reaction of donor-acceptor cyclopropanes with 1,3-diphenylisobenzofuran. Lewis acid effect on the reaction pathway
作者:A. O. Chagarovskiy、O. A. Ivanova、E. M. Budynina、E. L. Kolychev、M. S. Nechaev、I. V. Trushkov、M. Ya. Mel’nikov
DOI:10.1007/s11172-013-0349-x
日期:2013.11
Sn(OTf)2, SnCl2, ZnCl2, GaCl3, and MgI2, proceeds as a formal [3+4]-cycloaddition leading to a newly formedseven-memberedring. This reaction was found to be typical of cyclopropane-1,1-diesters and dinitriles, as well as 1-nitrocyclo-propanecarboxylates containing aromatic, heteroaromatic, and vinylicsubstituents at the C(2) atom of the small ring. When Me3SiOTf, TiCl4, SnCl4, or BF3·OEt2 were used as initiators