采用一维核Overhauser效应（1D NOE）和梯度异核多键相关（gHMBC）核磁共振技术对区域异构体3-[2-或5-苯胺基-2-(烷基氨基)苯基]丙酸、2H-1,4-苯并噻嗪-3(4H)-酮和2,3-二氢-1,5-苯并硫氮杂䓬-4(5H)-酮进行结构归属。

Structural assignment of regioisomeric 3-[2- or 5-anilino-2-(alkylamino)phenyl]propanoic acids, 2H-1,4-benzothiazin-3(4H)-ones and 2,3-dihydro-1,5-benzothiazepin-4(5H)-ones by 1D NOE and gHMBC NMR techniques.

作者信息

Katritzky Alan R, Akhmedov Novruz G, Wang Mingyi, Rostek Charles J, Steel Peter J

机构信息

Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200, USA.

出版信息

Magn Reson Chem. 2004 Jul;42(7):648-58. doi: 10.1002/mrc.1373.

DOI:10.1002/mrc.1373

PMID:15181636

Abstract

The 1H and 13C NMR spectra of compounds 1-11 and 16-22 in CDCl3 and DMSO-d6 solutions allowed structural assignment to regioisomers 1/5 and 2/6 and their regioselective cyclization products 16-18 utilizing one- and two-dimensional NMR techniques (APT, DEPT, NOE difference, COSY, NOESY, HETCOR and gHMQC, gHMBC). Temperature-dependent 1H NMR spectra of 8-anilino-5-(4-methyl-2-pentyl)-2,3-dihydro-1,5-benzothiazepin-4(5H)-one (18) indicated a free energy of activation (deltaG++) of ca 17 kcal mol(-1) for interconversion between rotamers. The 1H and 13C NMR spectra of 20 and 22 containing two chiral centers exhibit duplication of several signals, indicating the existence of two diastereomeric forms. The structure of 4 was unambiguously confirmed by x-ray crystallography.

摘要

化合物1 - 11以及16 - 22在CDCl₃和DMSO - d₆溶液中的¹H和¹³C NMR光谱，利用一维和二维NMR技术（APT、DEPT、NOE差异、COSY、NOESY、HETCOR以及gHMQC、gHMBC），实现了对区域异构体1/5和2/6及其区域选择性环化产物16 - 18的结构归属。8 - 苯胺基 - 5 -（4 - 甲基 - 2 - 戊基）- 2,3 - 二氢 - 1,5 - 苯并硫氮杂䓬 - 4(5H)- 酮（18）的变温¹H NMR光谱表明，旋转异构体之间相互转化的活化自由能（ΔG⁺⁺）约为17 kcal mol⁻¹。含有两个手性中心的20和22的¹H和¹³C NMR光谱显示出几个信号的重复，表明存在两种非对映体形式。4的结构通过X射线晶体学得到明确证实。