The aryl amidoximes R'C6H4C(NH2)═NOH (R' = Me, 2a; H, 2b; CN, 2c; NO2, 2d) react with the dialkylcyanamide platinum(II) complexes trans-[PtCl2(NCNAlk2)2] (Alk2 = Me2, 1a; C5H10, 1b) in a 1:1 molar ratio in CHCl3 to form chelated mono-addition products [3a-h]Cl, viz. [PtCl(NCNAlk2){NH═C(NR2)ON═C(C6H4R')NH2}]Cl (Alk2 = Me2; R' = Me, a; H, b; CN, c; NO2, d; Alk2 = C5H10; R' = Me, e; H, f; CN, g; NO2, h). In the solution, these species spontaneously transform to the amidrazone complexes [PtCl2{NH═C(NR2)NC(C6H4R')NNH2}] (7a-h; 36-47%); this conversion proceeds more selectively (49-60% after column chromatography) in the presence of the base (PhCH2)3N. The observed reactivity pattern is specific for NCNAlk2 ligands, and it is not realized for conventional alkyl- and arylnitrile ligands. The mechanism of the cascade reaction was studied by trapping the isocyanate intermediates [PtCl(NCO){NH═C(NR2)NC(C6H4R')NNH2}] (5a-h) and also by ESI-MS identification of the ammonia complexes [PtCl(NH3){NH═C(NR2)NC(C6H4R')NNH2}](+) ([6a-h](+)) in solution. The complexes [3a]Cl, [3c-h]Cl, 5a-h and 7a-h were characterized by elemental analyses, high resolution ESI-MS, IR, and (1)H NMR techniques, while 5b, 5d, 5g, 7b, and 7e were also studied using single-crystal X-ray diffraction.
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http://dx.doi.org/10.1021/ic4000878 | DOI Listing |
Pharmaceuticals (Basel)
September 2022
Department of Organic Chemistry, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Jurasza Str. 2, 85-089 Bydgoszcz, Poland.
Amidrazones are widely used in chemical synthesis, industry and agriculture. We compiled some of the most important findings on the biological activities of amidrazones described in the years 2010-2022. The data were obtained using the ScienceDirect, Reaxys and Google Scholar search engines with keywords (amidrazone, carbohydrazonamide, carboximidohydrazide, aminoguanidine) and structure strategies.
View Article and Find Full Text PDFBiomolecules
September 2020
Institute of Inorganic Chemistry, University of Vienna, Währinger Strasse 42, A-1090 Vienna, Austria.
Thiosemicarbazones continue to attract the interest of researchers as potential anticancer drugs. For example, 3-aminopyridine-2-carboxaldehyde thiosemicarbazone, or triapine, is the most well-known representative of this class of compounds that has entered multiple phase I and II clinical trials. Two new triapine derivatives and were prepared by condensation reactions of 2-pyridinamidrazone and S-methylisothiosemicarbazidium chloride with 3--(-butyloxycarbonyl) amino-pyridine-2-carboxaldehyde, followed by a Boc-deprotection procedure.
View Article and Find Full Text PDFInorg Chem
June 2013
Department of Chemistry, Saint Petersburg State University, Universitetsky Pr. 26, 198504 Stary Petergof, Russian Federation.
The aryl amidoximes R'C6H4C(NH2)═NOH (R' = Me, 2a; H, 2b; CN, 2c; NO2, 2d) react with the dialkylcyanamide platinum(II) complexes trans-[PtCl2(NCNAlk2)2] (Alk2 = Me2, 1a; C5H10, 1b) in a 1:1 molar ratio in CHCl3 to form chelated mono-addition products [3a-h]Cl, viz. [PtCl(NCNAlk2){NH═C(NR2)ON═C(C6H4R')NH2}]Cl (Alk2 = Me2; R' = Me, a; H, b; CN, c; NO2, d; Alk2 = C5H10; R' = Me, e; H, f; CN, g; NO2, h). In the solution, these species spontaneously transform to the amidrazone complexes [PtCl2{NH═C(NR2)NC(C6H4R')NNH2}] (7a-h; 36-47%); this conversion proceeds more selectively (49-60% after column chromatography) in the presence of the base (PhCH2)3N.
View Article and Find Full Text PDFJ Inorg Biochem
September 2012
Faculty of Chemistry, Maria Curie-Sklodowska University, M.C. Skłodowskiej Sq. 2, 20-031 Lublin, Poland.
A new linear amidrazone derivative, 6-acetyl-cyclohex-3-enecarboxylic acid [1-pyridin-2-yl-1-(pyridyn-2-yloamin)meth-(Z)-ylidene] hydrazide, H(2)L (2) and its Cu(II) complex, [Cu(2)L(2)]·4H(2)O (3) were synthesized and characterized by elemental analysis, IR and (1)H NMR spectroscopy and cyclic voltammetry. Compound 2 was synthesized in the equimolar reaction of N(3)-substituted amidrazone with cis-1,2,3,6-tetrahydrophthalic anhydride. The Cu complex of 2 was obtained in the reaction with copper(II) acetate.
View Article and Find Full Text PDFDalton Trans
January 2011
Department of Chemistry, University of California, Berkeley, California 94720, USA.
A series of N(1),N(1),N(3)-tri-substituted benzamidrazones of the general formula [PhC(NHR)=NNMe(2)] (R = Me, n-Pr, i-Pr, n-Bu, Bn, Ph; 1a-f) was synthesized via condensation of 1,1-dimethylhydrazine with the corresponding imidoyl chloride, [PhC(Cl)=NR]. Multinuclear NMR data, and zero-point energy DFT calculations conducted with the B3LYP functional and 6-31G+(d,p) basis set, suggest that these compounds exist as a single tautomer in solution; possessing a weak intramolecular hydrogen bond and a structure dominated by the localised resonance structure ArC(NHR)=N-NMe(2). An X-ray crystallographic study upon PhC(NHPh)=NNMe(2) (1f) demonstrated that this compound adopts an identical tautomer in the solid state.
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