693-95-8Relevant articles and documents
Decarboxylation method for heterocyclic carboxylic acid compounds
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Paragraph 0034; 0035; 0041; 0050; 0051, (2019/05/11)
The invention relates to a decarboxylation method for heterocyclic carboxylic acid compounds. The method comprises the following steps: dissolving the heterocyclic carboxylic acid compounds in an aprotic polar solvent N,N-dimethylformamide, and performing decarboxylation at 85-150 DEG C with an organic acid as a catalyst. The method in the invention allows the yield of decarboxylation products obtained after a reaction to be higher than the yield of the products obtained through decarboxylation methods in the prior art, and does not need an expensive metal catalyst; and the solvent (DMF) in the present invention is more stable than DMSO, is not prone to decompose at a high temperature, and it can be recycled, so the cost is reduced. The method has the advantages of simple operation process, zero pollution, greenness, environmental protection and excellent application prospect.
A process for the preparation method of thiabendazole
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Paragraph 0061; 0081; 0086; 0087, (2018/04/01)
The invention relates to a new method for synthesizing thiabendazole. Acetone and chlorine are taken as starting materials to synthesize chloroacetone, chloroacetone not subjected to separation can directly react with thiocarbamide to obtain 2-Amino-4-methylthiazole which is subjected to diazotization to obtain 4-methylthiazole, and 4-methylthiazole is oxidized to produce 4-thiazolecarboxylic acid, and finally, 4-thiazolecarboxylic acid reacts with o-phenylenediamine to obtain the target object thiabendazole. The thiabendazole is a broad-spectrum anthelmintic, can repel roundworms, hookworms, whipworms, pinworms, strongyloises stercoralis and trichinization, is also a broad-spectrum efficient disinfectant and is widely used as a fruit fresh-keeping agent and a bactericidal mildew inhibitor in various fields over the past decade in China.
A TPD-MS study of the interaction of coumarins and their heterocyclic derivatives with a surface of fumed silica and nanosized oxides CeO 2/SiO2, TiO2/SiO2, Al 2O3/SiO2
Kulyk, Kostiantyn,Ishchenko, Valentyna,Palyanytsya, Borys,Khylya, Volodymyr,Borysenko, Mykola,Kulyk, Tetiana
scheme or table, p. 750 - 761 (2011/09/12)
The interactions between coumarins and the surface of fumed SiO 2, CeO2/SiO2, TiO2/SiO2 and Al2O3/SiO2 were assessed by means of temperature-programed desorption mass spectrometry. The different stages of the thermolysis of coumarin were identified and an analysis of the underlying reactions was performed. The kinetic parameters of the involved reactions were thus obtained. The decomposition of thiazolyl-substituted coumarins was found to proceed through a 'thiazole-thiazine' ring expansion in the adsorbed state. A linear correlation between the sigma constants (Σσ) of the coumarin substituents and the activation energy of CO2 formation was obtained. Copyright
Silver-catalyzed protodecarboxylation of heteroaromatic carboxylic acids
Lu, Pengfel,Sanchez, Carolina,Cornella, Josep,Larrosa, Igor
supporting information; experimental part, p. 5710 - 5713 (2010/02/28)
[Chemical Equation Presented] A simple and highly efficient protodecarboxylation procedure for a variety of heteroaromatic carboxylic acids catalyzed by Ag2CO3 and AcOH in DMSO is described. This methodology can also perform the selective monoprotodecarboxylation of several aromatic dicarboxylic acids.
Reactivity of neutral nitrogen donors in square-planar d8 metal complexes: The system chloro(2,2′:6′,2″-terpyridine)platinum(II) cation with five-membered N-donor heterocycles in methanol
Pitteri, Bruno,Bortoluzzi, Marco
, p. 2698 - 2704 (2008/10/09)
The kinetics of the forward and reverse steps of the reaction [Pt(terpy)Cl]+ + nu ? [Pt(terpy)(nu)]2+ + Cl- (terpy = 2,2′:6′,2″-terpyridine, nu = one of a number of thiazoles, oxazole, isoxazole, imidazole, pyrazole and 3,5-dimethylpyrazole, covering a wide range of basicities) have been studied in methanol at 25 °C. Both forward and reverse reactions obey the usual two-term rate law observed in square-planar substitution. The second-order rate constants for the forward reactions, k2f, show a slight dependence upon the basicity of the entering nu, while the steric hindrance due to the presence of one methyl group in the α position to the nitrogen markedly decreases the reactivity. The second-order rate constants for the reverse reactions, k2r, are very sensitive to the nature of the leaving group and a plot of log k2r against the pKa of the conjugate acids of the unhindered five-membered N-donors is linear with a slope of -0.51. The results are compared with data from the literature regarding a series of pyridines reacting with the [Pt(terpy)Cl]+ cation under the same experimental conditions. Both in the forward and in the reverse reaction, the reactivity depends not only upon the ligand basicity but also upon the nature of the nucleophile in the order: (thiazoles, oxazole, isoxazole, imidazole, pyrazoles) > pyridines for the entry of N-donors and on the contrary for the displacement by Cl-. Steric retardation, due to the presence of a methyl group in the α position to the nitrogen, is remarkably lower for five-membered N-donors if compared to pyridines both in the forward and in the reverse reaction.
Thiazole, imidazole and oxazole compounds and treatments of disorders associated with protein aging
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, (2008/06/13)
Provided are, among other things, compounds of formula I or IA, . Also provided are methods of treatment with such compounds.
Method for treating glaucoma IIB
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, (2008/06/13)
Provided is a method of decreasing intraocular pressure or improving ocular accommodation in an animal, including a human, comprising administering an intraocular pressure decreasing amount or ocular accommodation improving amount of a compound of the formula I or IA, wherein J is oxygen, sulfur, or N—Rd.
1,2,3-Benzothiadiazole derivatives
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, (2008/06/13)
Novel 1,2,3-benzothiadiazole derivatives of the formula STR1 in which Het has the meanings set forth in the specification, and addition products thereof with an acid or metal salt are very effective for the control of undesired microorganisms. Novel intermediates of the formulae STR2 in which Het1 and R5 have the meanings given in the specification.
Chloropyridylcarbonyl derivatives
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, (2008/06/13)
Novel chloropyridylcarbonyl derivatives of the formula STR1 in which Het is STR2 n is 1 or 2, R1 is hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C3-6 alkynyl, optionally substituted phenyl or optionally substituted pyrimidinyl, and R2 and R3, independently of each other, are hydrogen or C1-4 alkyl, and acid addition salts and metal salt complexes thereof, are outstandingly active as microbicides.
Phototransposition Chemistry of 4-Substituted Isothiazoles. The P4 Permutation Pathway
Pavlik, James W.,Tongcharoensirikul, Pakamas,French, Kathleen M.
, p. 5592 - 5603 (2007/10/03)
Upon irradiation in the presence of a small quantity of base, 4-substituted isothiazoles undergo photocleavage to yield substituted cyanosulfides, which can be trapped as their benzyl thioether derivatives, and substituted isocyanosulfides. Both products are suggested to arise via initial photocleavage of the sulfur-nitrogen bond, resulting in the formation of a substituted β-thioformylvinyl nitrene, which can rearrange to the observed cyanosulfide, or cyclize to an undetected thioformylazirine. Deprotonation of the azirine leads directly to the isocyanosulfide. The plight of the isocyanosulfide depends on the C-4 substituent. If the substituent is aromatic, the isocyanosulfide is reprotonated at the isocyanide carbon and spontaneously cyclizes to a 4-substituted thiazole, the observed transposition product. If the substituent is not aromatic, the isocyanosulfide is reprotonated at sulfur and the resulting species has a higher energy barrier to cyclization. In these cases, the isocyanosulfides can be observed spectroscopically and can be trapped as their N-formylaminobenzyl thioether derivatives.
