123-33-1Relevant academic research and scientific papers
Triethanolamine as an inexpensive and efficient catalyst for the green synthesis of novel 1H-pyrazolo[1,2-a]pyridazine-5,8-diones under ultrasound irradiation in water and their antibacterial activity
Khoraamabadi-Zad, Ahmad,Azadmanesh, Mohammad,Karamian, Roya,Asadbegy, Mostafa,Akbari, Maryam
, p. 47721 - 47725 (2014)
Triethanolamine was found to be an efficient catalyst for the synthesis of new 1H-pyrazolo[1,2-a]pyridazine-5,8-diones by a one-pot reaction of maleic hydrazide, with aromatic aldehydes and malononitrile in H2O under ultrasonic irradiation. The advantages of this method are the use of an inexpensive and readily available catalyst, easy workup, improved yields, and the use of H2O as a green solvent. To assess their antibacterial activity, all the synthesized compounds were dissolved in DMSO and subjected to biological evaluation using the disc diffusion method against 3 Gram positive and 3 Gram negative bacteria. This journal is
UV-induced photoisomerization of maleic hydrazide
Reva, Igor,Almeida, Bruno J. A. N.,Fausto, Rui,Lapinski, Leszek
, p. 74 - 83,10 (2012)
Monomers of maleic hydrazide (3-hydroxypyridazin-6-one) were studied using the experimental matrix-isolation technique as well as DFT and QCISD methods of quantum chemistry. The oxo-hydroxy tautomer was theoretically predicted to be the most stable form o
Synthesis of new derivatives of pyridazino[6,1-c]pyrimido[5,4-e][1,2,4]triazine; a novel heterocyclic system
Akaberi, Toktam,Shiri, Ali,Sheikhi-Mohammareh, Seddigheh
, p. 44 - 46 (2016)
Several derivatives of the novel pyridazino[6,1-c]pyrimido[5,4-e][1,2,4]triazine ring system have been synthesised through heterocyclisation of 5-bromo-2,4-dichloro-6-methylpyrimidine with 3-chloro-6-hydrazinylpyridazine followed by treatment with secondary amines in boiling ethanol.
Highly Chemoselective Synthesis of Novel 6- O -phosphorylated 6-Hydroxypyridazine-3(2H)-one
Ju, Zhiyu,Li, Gongchun,Wang, Mei,Yang, Fengling,Ye, Yong,Zhao, Yufen
, p. 79 - 84 (2015)
6-O-Phosphorylated pyridazine-3(2H)-one derivatives were conveniently prepared by a facile method. Maleic hydrazide was prepared by the condensation of maleic anhydride with 85% hydrazine hydrate. It was then chemoselectively phosphorylated at the 6-O position using the Atherton-Todd reaction. An efficient, highly chemoselective method to synthesize 6-O-phosphorylated pyridazin-3(2H)-one derivatives is provided, and the approach has the merits of mild reaction conditions. GRAPHICAL ABSTRACT.
Dramatically enhanced fluorescence of heteroaromatic chromophores upon insertion as spacers into oligo(triacetylene)s
Edelmann, Michael J.,Raimundo, Jean-Manuel,Utesch, Nils F.,Diederich, Francois,Boudon, Corinne,Gisselbrecht, Jean-Paul,Gross, Maurice
, p. 2195 - 2213 (2002)
In continuation of a previous study on the modulation of π-electron conjugation of oligo(triacetylene)s by insertion of central hetero-spacer fragments between two (E)-hex-3-ene-1,5-diyne ((E)-1,2-diethynylethene, DEE) moieties (Fig. 1), a new series of trimeric hybrid oligomers (14-18 and 22-24, Fig. 2) were prepared (Schemes 1-3). Spacers used were both electron-deficient (quinoxaline-based heterocycles, pyridazine) and electron-rich (2,2′-bithiophene, 9,9-dioctyl-9H-fluorene) chromophores. With 19-21 (Scheme 4), a series of transition metal complexes was synthesized as potential precursors for nanoscale scaffolding based on both covalent acetylenic coupling and supramolecular assembly. The UV/VIS spectra (Fig. 3) revealed that the majority of spacers provided heterotrimers featuring extended π-electron delocalization. The new hybrid chromophores show a dramatically enhanced fluorescence compared with the DEE dimer 13 and homo-trimer 12 (Fig. 5). This increase in emission intensity appears as a general feature of these systems: even if the spacer molecule is non-fluorescent, the corresponding hetero-trimer may show a strong emission (Table 2). The redox properties of the new hybrid chromophores were determined by cyclic voltammetry (CV) and rotating-disk voltammetry (RDV) (Table 3 and Fig. 5). In each case, the first one-electron reduction step in the hetero-trimers appeared anodically shifted compared with DEE dimer 13 and homo-trimer 12. With larger spacer chromophore extending into two dimensions (as in 14-18, Fig. 2), the anodic shift (by 240-490 mV, Table 3) seems to originate from inductive effects of the two strongly electron-accepting DEE substituents rather than from extended π-electron conjugation along the oligomeric backbone, as had previously been observed for DEE-substituted porphyrins.
Synthesis and anticonvulsant activity of novel 1-substituted-1,2-dihydro-pyridazine-3,6-diones.
Sivakumar, Ramaiah,Anbalagan, Navaneetharaman,Gunasekaran, Vedachalam,Leonard, Joseph Thomas
, p. 1407 - 1411 (2003)
The synthesis and pharmacological evaluation of novel 1-substituted-1,2-dihydro-pyridazine-3,6-diones (4a--l, 5a--j) as potential anticonvulsant agents are described. The compounds were tested in vivo for the anticonvulsant activity. The compound which have maximum protection against MES induced seizures is 1-[3-(2-aminophenylamino)-2-hydroxypropyl)-1,2-dihydro-pyridazine-3,6-dione 4h (ED(50)=44.7 mg x kg(-1) i.p.) 1-[2-hydroxy-3-piperazin1-yl-propyl)-1,2-dihydro-pyridazine-3,6-dione 4c (ED(50)=72 mg x kg(-1) i.p.) and 1-[2-hydroxy-3-imidazol-1-yl-propyl)-1,2-dihydro-pyridazine-3,6-dione 4d (ED(50)=79 mg x kg(-1) i.p.) were also found to have maximum protection against MES induced seizures. Whereas all these compounds failed to protect the animals from subcutaneous pentylenetetrazole (Metrozol) seizure threshold test (sc-Met).
The Mechanism of Thermal Eliminations. Part 18. Relative Rates of Pyrolysis of 2-Ethoxypyrazine, 3-Ethoxypyridazine, 2-and 4-Ethoxypyrimidine, 3-Chloro-6-ethoxypyridazine, and 2-Chloro-4-ethoxypyrimidine : the Effect of the Aza 'Substituent' and ?-Bond Order on the Elimination Rate
Al-Awadi, Nouria,Taylor, Roger
, p. 1255 - 1258 (1986)
A kinetic study has been made of the first-order thermal decomposition of the title compounds into ethylene and the corresponding aza-substituted pyridines, between 650 and 713 K.The relative elimination rates at 650 K are (2-ethoxypyridine = 1): 0.545, 10.0, 1.03, 1.12, 9.68, and 3.28, respectively.The electronic effects of the aza 'substituent' are small, and a more important factor appears to be the C-N ?-bond order; this latter accounts for the high reactivity of the pyridazines.The effects of the chloro substituent and of the aza 'substituent' are explicable in terms of a balance between electron withdrawal from the C-O bond (producing deactivation) and from the nitrogen involved in the cyclic transition state (producing deactivation).The effects of the chloro substituents confirm that the most important step of the reaction is breaking of the C-O bond.The statistically corrected rate (per ring nitrogen) of 2-ethoxypyrimidine is unexpectedly low.This may reflect difficulty in achieving the coplanar transition state in which the lone pairs in the s-orbitals of oxygen and the nitrogen not involved in the elimination are brought into close proximity.
Liquid Phase Synthesis of 1,2-Dihydropyridazine-3,6-dione in the Presence of Ionite Catalysts
Baeshov, A. B.,Dzhumadullaeva, S. A.
, p. 954 - 957 (2021/06/07)
Abstract: The catalytic activity of synthetic ion-exchange resins was studied in the reaction between cis-butenedioic acid and hydrazine (aqueous medium; temperature, 95°C; 2–4 h) with the formation of heterocyclic hydrazide–1,2-dihydropyridazine-3,6-dione. It is established that the most effective catalysts are KU?2-8 and KRF-10P cation exchangers. A probable mechanism of the process with the formation of adsorption complexes and the participation of fixed polymer-bound sulfonate ions and counterions of the cation exchanger is proposed on the basis of IR spectroscopic studies.
Preparation method of 3, 6-dihydroxypyridazine
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Paragraph 0023-0028; 0036-0063, (2020/07/08)
The invention provides a preparation method of 3, 6-dihydroxypyridazine, which comprises the following step: by using maleic anhydride and hydrazine hydrate as raw materials and 1, 3-diene substance as a catalyst, performing reaction to obtain the product 3, 6-dihydroxypyridazine. Finally, the reaction can be carried out for a short time at a relatively low temperature, so that the product 3, 6-dihydroxypyridazine can be obtained with high yield and high purity. In the later period of reaction, a certain amount of organic matter containing two or more hydrophilic groups is added into the system, reaction is conducted for a period of time at high temperature, the content of harmful impurity amine substances in the product can be remarkably reduced, the product quality is remarkably improved, the requirements of high-end markets such as European and American markets are met, and adverse effects on the yield of the product at high temperature are avoided. The 1, 3-diene substance catalystused in the method is recovered in the heating stage and is recycled, the environmental protection requirement is met, the cost is reduced, and energy conservation and emission reduction are achieved.
COMPOSITIONS OF DICARBOXYLIC ACID DERIVATIVES
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Page/Page column 12; 13, (2021/01/22)
The present invention relates to agricultural compositions containing dicarboxylic acid hydrazides and transition metal ions, and the preparation thereof. The compositions are useful in the treatments of plants or seeds as an anti-sprout agent, growth regulator and/or pest control agent. In particular, it relates to maleic hydrazide combined with copper, nickel, manganese, iron or zinc. The transition metal ions improve the storage stability of the dicarboxylic acid hydrazide and prevent generation of free hydrazine.
