sterically hindered tert-butylamine. The 1H NMR spectra of the synthesized, new, unsymmetrical ureas carried out in [D6]DMSO suggest that the protons in the –αCH–NHCONH–CH– moiety assume a trans conformation. Moreover, analysis of the mass spectra (EI and ESI) revealed some interesting common features. The reported synthesis represents the first example of the potential value of carbamoyl azides as versatile
A fast and simple one-pot synthesis of carbamoylazides of α-N-protected amino acids is reported. The procedure involves the reaction between sodium azide and the mixed anhydride obtained from an α-N-protected amino acid and isobutyl chloroformate, in the presence of KH 2 PO 4 . The reaction rate was influenced by the nature of both the α-N-protection and the amino acid side chain. Surprisingly, T
报道了一种快速简单的一锅法合成 α-N-保护氨基酸的氨基甲酰叠氮化物。该过程涉及叠氮化钠与由α-N-保护的氨基酸和氯甲酸异丁酯获得的混合酸酐在KH 2 PO 4 存在下的反应。反应速率受α-N-保护和氨基酸侧链的性质影响。令人惊讶的是,叔丁氧羰基 (α-N-Boc) 和苄基氧羰基 (α-N-Cbz) 保护的脯氨酸提供了相应的异氰酸酯,而不是预期的氨基甲酰基叠氮化物。
Design and Synthesis of Novel Symmetric Fluorene-2,7-Diamine Derivatives as Potent Hepatitis C Virus Inhibitors
作者:Mai H. A. Mousa、Nermin S. Ahmed、Kai Schwedtmann、Efseveia Frakolaki、Niki Vassilaki、Grigoris Zoidis、Jan J. Weigand、Ashraf H. Abadi
DOI:10.3390/ph14040292
日期:——
HepatitisCvirus (HCV) is an international challenge. Since the discovery of NS5A direct-acting antivirals, researchers turned their attention to pursue novel NS5A inhibitors with optimized design and structure. Herein we explore highly potenthepatitisCvirus (HCV) NS5A inhibitors; the novel analogs share a common symmetrical prolinamide 2,7-diaminofluorene scaffold. Modification of the 2,7-diaminofluorene
Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 17.1 Preparation of aliphatic amino acid derived γ-alkoxycarbonylamino-β-oxo ylides and pyrolysis to give α,β-acetylenic γ-amino acid and GABA analogues
作者:R. Alan Aitken、Nazira Karodia、Tracy Massil、Robert J. Young
DOI:10.1039/b110243e
日期:2002.2.6
A series of eleven α-aminoacyl stabilised phosphorus ylides 9â19 have been prepared by condensation of N-alkoxycarbonyl protected amino acids with Ph3PCHCO2Et using a carbodiimide peptide coupling reagent. Upon flash vacuum pyrolysis at 600 °C, these undergo extrusion of Ph3PO to give the corresponding α,β-acetylenic γ-amino esters 21â29, 33 and 34 in moderate yield. In two cases the terminal alkynes 30 and 31 are also formed. The β-aminoacyl ylide 20 from β-alanine
similarly gives the α,β-acetylenic δ-amino ester 35 upon pyrolysis. Regioselective addition of HBr to the triple bond of one acetylenic ester 25 was observed giving a mixture of E and Z
α-bromoacrylates 36. Hydrogenation of the N-Cbz acetylenic esters 21â23 and 33 results in N-deprotection and hydrogenation of the triple bond to afford the chiral GABA analogues 37â40 in 70 â>95% ee as determined by 19F NMR of their Mosher amides. Fully assigned 13C NMR spectra of all the ylides and acetylenic ester derivatives are presented.
Expanding the chemical space of anti-HCV NS5A inhibitors by stereochemical exchange and peptidomimetic approaches
作者:Triveena M. Ramsis、Shereen E. Abdel Karim、Niki Vassilaki、Efseveia Frakolaki、Ahmed A. M. Kamal、Grigoris Zoidis、Nermin S. Ahmed、Ashraf H. Abadi
DOI:10.1002/ardp.201800017
日期:2018.7
Here we report a series of potent anti‐HCV agents bearing a symmetrical benzidine l‐prolinamide backbone with different capping groups including alkyl/aryl carbamates of natural and unnatural valine and leucine amino acids. All compounds were investigated for their inhibitory activity in an HCV replicon assay on genotype 1b. The novel compounds share some chemical and clinical attributes of commercially