4233-33-4Relevant academic research and scientific papers
Oxidative dehydrogenation of 4-arylurazoles
Wamhoff,Zlotskii,Saprygina
, p. 332 - 332 (2002)
4-Arylurazoles are selectively oxidized with Fe2(NO 3)3·9H2O to the corresponding Δ1-1,2,4-triazoline-3,5-diones.
Role of Heteroatoms in Diastereofacial Control in Cycloaddition to a Dissymmetric Cyclohexa-1,3-diene Moiety in a Polycyclic Framework. Remarkable Stereodirecting Influence of Distal Protective Groups
Mehta, Goverdhan,Uma
, p. 1685 - 1696 (2000)
Diels-Alder cycloaddition to several derivatives of a facially dissymmetric diene, the hexacyclo-[7.5.1.0.1,60.6,130.8,120. 10,14]pentadeca-2,4-diene-7,15-dione 4a, with a variety of dienophiles such as singlet oxygen, N-phenyltriazolinedione, dimethyl acetylenedicarboxylate, maleic anhydride, and N-methylmaleimide has been studied. The stereochemistry of the resulting adducts has been unambiguously secured by 1H and 13C NMR spectral data, chemical correlations, and X-ray crystal structure determination. While a variety of dienophiles undergo [4 + 2]-cycloadditions with 4a predominantly from the carbonyl face, protection of the carbonyl groups in 4a as simple mono- or bis-acetals 4b-e or thioacetals 9a,b leads to complete reversal in selectivity, favoring addition from the cyclobutane face, with heterodienophiles and acetylenic dienophiles. The reversal in selectivity observed in mono- and bis-acetals 4b-e has been attributed to unfavorable electrostatic interaction between the oxygen atom and the incoming dienophile. Whereas, in the case of thioacetals 9a,b, apart from unfavorable electrostatic interactions, Cieplak-type hyperconjugative interactions have to be given due consideration in order to account for the observed selectivities. Our studies highlight the role of simple protective groups (acetals in the present case) in modulating diastereoselection during [4 + 2]-cycloadditions.
METHOD FOR PRODUCING SOLID TRIAZOLINEDIONE COMPOUND, SOLID TRIAZOLINEDIONE COMPOUND, AND METHOD FOR PRODUCING TRIAZOLINEDIONE COMPOUND
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Paragraph 0160-0163, (2020/12/25)
Provided are a method for separating a DAPTAD-containing triazolinedione compound in solid form from a reaction solution, a separated solid triazolinedione compound, and a novel method for producing a triazolinedione compound. A triazolinedione solution in which a DAPTAD-containing triazolinedione compound is dissolved is brought into contact with a C5-15 hydrocarbon-based poor solvent to obtain a solid triazolinedione compound. Also, a triazolinedione compound is oxidized using an oxidizing agent that does not produce acid as a byproduct to obtain a triazolinedione compound.
Diazacyclobutene derivatives and methods of synthesis thereof
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Page/Page column 12, (2021/01/17)
Provided is a compound having the formula: wherein: R1 is selected from the group consisting of H, aliphatic of 1 to 100 carbons and arene comprising up to 100 carbons; R2 is selected from the group consisting of H, aliphatic of 1 to 100 carbons and arene comprising up to 100 carbons; each R3 is independently selected from the group consisting of H, aliphatic of 1 to 100 carbons and arene comprising up to 100 carbons; X is selected from the group consisting of B, O, N, S, Se and P; and n is 1-4 as necessary to complete the valence of X formed by the reaction of a compound of Formula III: and a compound of Formula IV:
1,2-Diazacyclopentane-3,5-diyl Diradicals: Electronic Structure and Reactivity
Yoshidomi, Shohei,Abe, Manabu
supporting information, p. 3920 - 3933 (2019/03/07)
Localized singlet diradicals are key intermediates in bond homolysis. A thorough study of the reactive species is needed to clarify the mechanisms of the homolytic bond cleavage and formation processes. In general, the singlet diradicals are quite short-lived because of the fast radical-radical coupling reactions. The short-lived characteristic has retarded the thorough study on bond homolysis. In this study, a new series of long-lived singlet diradicals, viz., 1,2-diazacyclopentane-3,5-diyl, were identified, and their electronic structures and novel reactivities were thoroughly studied using laser-flash photolysis (LFP), product analysis, and computational studies. A direct observation of the thermal equilibration (fast process) between the singlet diradicals and the corresponding ring-closing compounds was undertaken on the submicrosecond time scale. The solvent and substituent effects on the equilibration constant and rate constants for the ring-closing reaction and ring-opening reaction clarify the novel nitrogen-atom effect on the localized singlet 1,3-diyl diradicals. Two types of alkoxy-migrated compounds, 9 and 10, were isolated with high yields as the final products. Crossover, spin-trapping, and LFP experiments for the formation of alkoxy-group migration products (i.e., 9 versus 10) revealed the unique temperature effect on the product ratio of the two types of alkoxy-migration products. The temperature-insensitive intersystem crossing process (slow process, millisecond time scale) was found to be a key step in the formation of 9, which is an entropy-controlled pathway. An intramolecular migration process was identified for the formation of 10 that was accelerated by a polar solvent in an enthalpy-controlled process. This unique heteroatom effect has opened up a new series of localized singlet diradicals that are crucial intermediates in bond homolysis.
[2π + 2π]-Cycloaddition of biadamantylidene to 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione. Effects of temperature, high pressure, and solvent
Kiselev,Kornilov,Anikin,Sedov,Konovalov
, p. 1864 - 1869 (2018/02/06)
The effects of temperature, solvent nature, and high hydrostatic pressure on the rate of the reaction of biadamantylidene with 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione have been estimated. Significant shielding of the C=C double bond in biadamantylidene is responsible for the high entropy and volume of activation. Quantitative yield of the reaction in the temperature range 25?45°C is related to its exothermicity. The rate of the [2π + 2π]-cycloaddition unexpectedly weakly depends on the solvent polarity, which makes it radically different from the [2π + 2π]-reaction with tetracyanoethylene.
Method for preparing 3,5-dioxo-1,2,4-triazole
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Paragraph 0046; 0047; 0048; 0049; 0050; 0051, (2016/10/27)
The invention provides a method for preparing 3,5-dioxo-1,2,4-triazole. The method is characterized in that WO3-x nanosheets with oxygen vacancies are taken as a catalyst under the acidic condition, hydrated sodium tungstate is taken as a raw material, an appropriate quantity of additives are added to a solvent, and 3,5-dioxo-1,2,4-triazole is further directly synthesized through solvent heat or with a direct heating method; the WO3-x nanosheets with the oxygen vacancies are firstly prepared, tungsten oxide nanosheets catalyze and oxidize sulfur oxide, and 3,5-dioxo-1,2,4-triazole is prepared. According to the method, the reaction conditions are simple, the cost is low, no pollution is caused, and the method has important industrial application value and important environmental and social meaning.
Kinetic and equilibrium parameters of [4+2] cycloaddition reaction of 2,6-dimethylnaphthalene with 4-phenyl-1,2,4-triazoline-3,5-dione
Kiselev,Kashaeva,Potapova,Kornilov,Konovalov
, p. 770 - 771 (2015/01/30)
Kinetic parameters of forward and retro Diels-Alder reactions between 2,6-dimethylnaphthalene and 4-phenyl-1,2,4-triazolinedione were determined, as well as the equilibrium parameters of the reaction in 1,2-dichloroethane.
Features of the Diels-Alder reaction between 9,10-diphenylanthracene and 4-phenyl-1,2,4-triazoline-3,5-dione
Kiselev,Kornilov,Kashaeva,Potapova,Krivolapov,Litvinov,Konovalov
, p. 2073 - 2080 (2015/02/19)
The Diels-Alder reaction between substituted anthracenes 1a-1j and 4-phenyl-1,2,4-triazoline-3,5 (2) is studied. In all cases except one, the reaction proceeds on the most active 9,10-atoms of substituted anthracenes. The orthogonality of the two phenyl groups at the 9,10-position of diene 1a is found to shield 9,10-reactive centers. No dienophiles with C=C bonds are shown to participate in the Diels-Alder reaction with 1a; however, the reaction 1a + 2 proceeds with the very active dienophile 2,4-phenyl-1,2,4-triazoline-3,5-dione. It is shown that attachment occurs on the less active but sterically accessible 1,4-reactive center of diene 1a. The structure of adduct 3a is proved by 1H and 13C NMR spectroscopy and X-ray diffraction analysis. The following parameters are obtained for reaction 1a + 2 ? 3a in toluene at 25°C: Keq = 2120 M-1, ΔHf≠ = 58.6 kJ/mol, ΔSf≠ = -97 J/(mol K), ΔVf≠ = -17.2 cm3/mol, ΔHb ≠ = 108.8 kJ/mol, ΔSb≠ = 7.3 J/(mol K), ΔVb≠ = -0.8 cm3/mol, ΔHr-n = -50.2 kJ/mol, ΔSr-n = -104.3 J/(mol K), ΔVr-n = -15.6 cm3/mol. It is concluded that the values of equilibrium constants of the reactions 1a-1j + 2 ? 3a-3j vary within 4 × 101-1011 M-1.
Facile and stabile linkages through tyrosine: Bioconjugation strategies with the tyrosine-click reaction
Ban, Hitoshi,Nagano, Masanobu,Gavrilyuk, Julia,Hakamata, Wataru,Inokuma, Tsubasa,Barbas, Carlos F.
, p. 520 - 532 (2013/06/05)
The scope, chemoselectivity, and utility of the click-like tyrosine labeling reaction with 4-phenyl-3H-1,2,4-triazoline-3,5(4H)-diones (PTADs) is reported. To study the utility and chemoselectivity of PTAD derivatives in peptide and protein chemistry, we synthesized PTAD derivatives possessing azide, alkyne, and ketone groups and studied their reactions with amino acid derivatives and peptides of increasing complexity. With proteins we studied the compatibility of the tyrosine click reaction with cysteine and lysine-targeted labeling approaches and demonstrate that chemoselective trifunctionalization of proteins is readily achieved. In particular cases, we noted that PTAD decomposition resulted in formation of a putative isocyanate byproduct that was promiscuous in labeling. This side reaction product, however, was readily scavenged by the addition of a small amount of 2-amino-2-hydroxymethyl-propane- 1,3-diol (Tris) to the reaction medium. To study the potential of the tyrosine click reaction to introduce poly(ethylene glycol) chains onto proteins (PEGylation), we demonstrate that this novel reagent provides for the selective PEGylation of chymotrypsinogen, whereas traditional succinimide-based PEGylation targeting lysine residues provided a more diverse range of PEGylated products. Finally, we applied the tyrosine click reaction to create a novel antibody-drug conjugate. For this purpose, we synthesized a PTAD derivative linked to the HIV entry inhibitor aplaviroc. Labeling of the antibody trastuzumab with this reagent provided a labeled antibody conjugate that demonstrated potent HIV-1 neutralization activity demonstrating the potential of this reaction in creating protein conjugates with small molecules. The tyrosine click linkage demonstrated stability to extremes of pH, temperature, and exposure to human blood plasma indicating that this linkage is significantly more robust than maleimide-type linkages that are commonly employed in bioconjugations. These studies support the broad utility of this reaction in the chemoselective modification of small molecules, peptides, and proteins under mild aqueous conditions over a broad pH range using a wide variety of biologically acceptable buffers such as phosphate buffered saline (PBS) and 2-amino-2-hydroxymethyl- propane-1,3-diol (Tris) buffers as well as others and mixed buffered compositions.
