Synthese von Amidrazonen aus Amidinen

Neunhoeffer, Hans; Weischedel, Fritz

doi:10.1002/jlac.19717490104

Cited by 30 publications

(13 citation statements)

References 8 publications

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“…3,5-Di- tert -butyl-2-hydroxybenzaldehyde S-methylisothiosemicarbazone was prepared by condensation reaction of equimolar amounts of 3,5-di- tert -butyl-2-hydroxybenzaldehyde and S-methylisothiosemicarbazide hydroiodide in EtOH/H 2 O 1:1 followed by addition of equivalent amount of Na 2 CO 3 . Acetamidrazone hydrochloride was prepared as described in the literature 24. Condensation reaction between 3,5-di- tert -butyl-2-hydroxybenzaldehyde and acetamidrazone hydrochloride in ethanol/water 2:1 in the presence of equimolar amount of Na 2 CO 3 afforded a Schiff base.…”

Section: Methodsmentioning

confidence: 99%

Syntheses, Electronic Structures, and EPR/UV−Vis−NIR Spectroelectrochemistry of Nickel(II), Copper(II), and Zinc(II) Complexes with a Tetradentate Ligand Based on S-Methylisothiosemicarbazide

Arion¹,

Rapta²,

Telser³

et al. 2011

Inorg. Chem.

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Template condensation of 3,5-di-tert-butyl-2-hydroxybenzaldehyde S-methylisothiosemicarbazone with pentane-2,4-dione and triethyl orthoformate at elevated temperature resulted in metal complexes of the type MIIL, where M = Ni, Cu and H2L = novel tetradentate organic ligand. These complexes are relevant to the active site of the copper enzymes galactose oxidase and glyoxal oxidase. Demetallation of NiIIL with gaseous hydrogen chloride in chloroform afforded the metal-free ligand H2L. Then by the reaction of H2L with Zn(CH3COO)2·2H2O in 1:1 molar ratio in chloroform/methanol 1:2 the complex ZnIIL(CH3OH) was prepared. The three metal complexes and the prepared ligand were characterized by spectroscopic methods (IR, UV–vis and NMR spectroscopy), X-ray crystallography and DFT calculations. Electrochemically generated one-electron oxidized metal complexes [NiL]+, [CuL]+ and [ZnL(CH3OH)]+ and the metal-free ligand cation radical [H2L]+• were studied by EPR/UV–vis–NIR and DFT calculations. These studies demonstrated the interaction between the metal ion and the phenoxyl radical.

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Section: Methodsmentioning

confidence: 99%

Syntheses, Electronic Structures, and EPR/UV−Vis−NIR Spectroelectrochemistry of Nickel(II), Copper(II), and Zinc(II) Complexes with a Tetradentate Ligand Based on S-Methylisothiosemicarbazide

Arion¹,

Rapta²,

Telser³

et al. 2011

Inorg. Chem.

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“…The reaction of hydroxyamidrazone 30 with dimethylglyoxal 31 in methanol affords 5,6-dimethyl-3-phenyl-1,2,4-triazine 4-oxide 32. 31 The condensation of amidrazone 33 with phenylglyoxal monooxime 34 occurs through the formation of hydrazone 35. The elimination of an ammonia molecule from compound 35 gives 3-methyl-6-phenyl-1,2,4-triazine 4-oxide 36 in a good yield.…”

Section: Methods For the Synthesis Of 124-triazine N-oxidesmentioning

confidence: 99%

1,2,4-TriazineN-oxides and their annelated derivatives

Kozhevnikov¹,

Русинов²,

Чупахин³

1998

Russ. Chem. Rev.

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This review deals with the synthesis and properties of 1,2,4-triazine N-oxides and their annelated derivatives. Methods for the incorporation of the N-oxide group in the 1,2,4-triazine ring by direct oxidation and cyclisation involving nitro, nitroso, and isonitroso groups are discussed. Reactions of 1,2,4-triazine N-oxides with electrophiles, nucleophiles, and dienophiles are considered. The effect of the N-oxide group on the chemical shifts in the 1 H, 13 C, and 14 N NMR spectra and the specific features of decomposition of 1,2,4-triazine N-oxides under electron impact are analysed. The bibliography includes 107 references.

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“…the amidine hydrochlorides 3, can be difficult. [15] For this reason we employed a new strategy and compounds 4 were synthesized in a one-pot synthesis, without isolation of the intermediates (Scheme 1), using wellchosen reaction times as described in the Experimental section. Initially, it was confirmed that no by-products were formed in each step.…”

Section: Results and Discussion Synthesismentioning

confidence: 99%

‘Green' Synthesis of 2-Substituted 6-Hydroxy-[3H]-pyrimidin-4-ones and 4,6-Dichloropyrimidines: Improved Strategies and Mechanistic Study

et al. 2015

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An improved route to 2-substituted 6-hydroxy-[3H]-pyrimidin-4-ones 4 and to 2-substituted 4,6-dichloropyrimidines 5 is reported. Without using highly toxic reactants, compounds 4 can be prepared conveniently in a one pot synthesis on a one mol scale with average yields up to 80 %. 4,6-Dichloropyrimidines 5, which are usually prepared in small quantities, are synthesized with average yields of 80 %, using up to 80 g of starting material. The mechanism of the chlorination of 4 is investigated computationally for the first time. The results suggest that the chlorination with phosphoryl chloride occurs in an alternating phosphorylation-chlorination manner (pathway 1) which is preferred over a sequence which starts with two phosphorylations. The investigated 4,6-dichloropyrimidines described herein form strong complexes with dichlorophosphoric acid but weak complexes with hydrochloric acid (generated during workup). These latter complexes explain the necessity of using aqueous sodium carbonate during the working up. In order to prevent possible formation of pyrimidinium salts between intermediates or the final dichloropyrimidines and unreacted hydroxypyrimidone, the latter could be deactivated with a strong acid such as dichlorophosphoric acid, thus allowing chlorination but prohibiting salt formation. Because of its general applicability to all nitrogen heterocycle chlorinations with phosphoryl chloride, the proposed route to dichloropyrimidines without solvent or side products, using less toxic reactants, is of general synthetic interest.

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Synthese von Amidrazonen aus Amidinen

Cited by 30 publications

References 8 publications

Syntheses, Electronic Structures, and EPR/UV−Vis−NIR Spectroelectrochemistry of Nickel(II), Copper(II), and Zinc(II) Complexes with a Tetradentate Ligand Based on S-Methylisothiosemicarbazide

Syntheses, Electronic Structures, and EPR/UV−Vis−NIR Spectroelectrochemistry of Nickel(II), Copper(II), and Zinc(II) Complexes with a Tetradentate Ligand Based on S-Methylisothiosemicarbazide

1,2,4-TriazineN-oxides and their annelated derivatives

‘Green' Synthesis of 2-Substituted 6-Hydroxy-[3H]-pyrimidin-4-ones and 4,6-Dichloropyrimidines: Improved Strategies and Mechanistic Study

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