VT-NMR and cytotoxic evaluation of some new ortho-(alkylchalcogen)acetanilides
作者:Susana S. Ramos、Sandra S. Almeida、Paula M. Leite、Renato E.F. Boto、Samuel Silvestre、Paulo Almeida
DOI:10.1016/j.tet.2014.09.055
日期:2014.11
Several novel atropisomeric N-alkyl-N-[(2-alkylchalcogen)phenyl]acetamides have been synthesized and fully characterized by H-1 and C-13 NMR, FTIR, and HRMS (FAB). The barriers of the restricted rotation about the N-aryl bond between the two atropisomeric forms were measured by accurate lineshape simulation of variable temperature NMR (VT-NMR) spectra obtained in DMSO-d(6) solution and ranged from 17.0 to 20.5 kcal/mol. The relationship between the structure of the different acetanilide moieties and both coalescence temperature and energy of rotation are herein discussed. Taking in mind the acetamide structural resemblances with nimesulide related compounds known by their anticancer activity, the in vitro cytotoxicity of 20 representative acetanilides, against human breast (MCF-7) and prostate (LNCaP) cancer cell lines as well as normal human dermal fibroblasts (NHDF) was also preliminary evaluated. Interestingly a selective antiproliferative activity was observed for cancerous cells with prominence to LNCaP within the most potent O- and/or N-benzylic and -hexyl acetanilides. (C) 2014 Elsevier Ltd. All rights reserved.
Synthesis and dynamic study of new ortho-(alkylchalcogen)acetanilide atropisomers. A second look at the hydrolysis of quaternary 2-methylbenzazol-3-ium salts
作者:Susana S. Ramos、Lucinda V. Reis、Renato E.F. Boto、Paulo F. Santos、Paulo Almeida
DOI:10.1016/j.tetlet.2013.07.123
日期:2013.10
corresponding ether, thioether or selenoether derivatives, depending on the starting benzazole salt, by trapping via alkylation with ethyl and hexyl iodides, in moderate to good yields. Reduction of the o-(alkylchalcogen)acetanilides so obtained afforded the corresponding o-(alkylchalcogen)anilines. This methodology provides potential access to o-(alkylchalcogen)anilines bearing up to three different N-alkyl