- Preparation method of triazine ring
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The invention belongs to the technical field of preparation of organic intermediates, and particularly relates to a preparation method of a triazine ring. The method comprises the following steps: adding 2-methyl thiosemicarbazide, diethyl oxalate and a mixed alcohol solvent into a reaction flask, dropwise adding a mixed base catalyst, carrying out cyclization reaction at 45-55 DEG C, performing acidifying with hydrochloric acid, performing cooling to 0-5 DEG C, and carrying out suction filtration to obtain a triazine ring crude product; dissolving the triazine ring crude product in distilled water at 65-70 DEG C, performing cooling to 10-15 DEG C, crystallizing to obtain a triazine ring wet product, and drying at 90-100 DEG C for 3-5 hours to obtain a triazine ring dry product. According to the preparation method, a new solvent system is not introduced, the reaction selectivity is high, side reactions are few, the solvent system is easy to recycle, and the product yield is high; the adopted raw materials are cheap, easy to obtain, low in cost and suitable for industrial amplification.
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Paragraph 0017; 0035-0050
(2021/05/08)
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- Tricyclic synthesis process of triazine
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The invention discloses a tricyclic synthesis process of triazine. The process includes reacting methyl hydrazine aqueous solution with ammonium thiocyanate, and then preparing an aminomethyl thioureamethanol solution by methanol; preforming cyclization reaction on the aminomethyl thiourea methanol solution with dimethyl oxalate and sodium methoxide, adjusting pH value with hydrochloric acid to remove excess sodium methoxide after the reaction is completed, and then filtering the mixture to obtain triazine cyclic sodium salt; preforming acid precipitation on the triazine ring sodium salt to obtain a triazine cyclic crude product; stirring and washing the triazine cyclic crude product with hot water, cooling, crystallizing, filtering and drying the product to obtain a triazine cyclic refined product. The process has high yield, low raw material cost, the labor intensity of workers is reduced, and the pollution of three wastes is reduced.
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Paragraph 0024-0031
(2019/04/06)
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- The use of mixed solvent to synthesize triazine ring new method
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The invention relates to a novel method for synthesizing thiotriazinone (TTZ) by using a mixed solvent. The synthetic process comprises the following steps: performing cyclization reaction on 2-methylthiosemicarbazide, the mixed solvent, diethyl oxalate and sodium methylate at 0-45 DEG C to generate triazine ring sodium salt, and acidifying through hydrochloric acid to obtain thiotriazinone. Due to the use of the mixed solvent, the system viscosity of the synthetic process is greatly improved, the TTZ cyclization yield is increased to be more than 90% (by 2-methylthiosemicarbazide), and the content of a byproduct-1-methyl-5-sulfydryl-1,2,4-triazole-3-methyl carboxylate is less than 0.002%, namely less than 20ppm.
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Paragraph 0022; 0023; 0024; 0025; 0026; 0027; 0028-0031
(2017/10/07)
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- Cephalosporin compounds and antibacterial agents
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Cephalosporin compounds of the formula (I): STR1 wherein R1 and R2 may be the same or different and are a hydrogen atom or a lower alkyl group of 1-5 carbon atoms and A is a hydrogen atom or a nucleophilic compound residue or pharmacologically acceptable salts thereof have excellent antibacterial activity against Gram positive and Gram negative microorganisms.
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- Cephalosporin derivatives and bactericides containing the same
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Cephalosporin compounds represented by the following formula (I) and pharmaceutically acceptable salts thereof have a broad bactericidal spectrum against various pathogenic bacteria including Psuedomonas aeruginosa and are useful as bactericidal remedies for pathogenic diseases of human and animals: STR1 wherein A represents an unsubstituted or substituted pyridylthio group of a formula (I-1); STR2 or an unsubstituted or substituted pyridiniumthio group of a formula (I-2): STR3 or an unsubstituted or substituted pyridinium group of a formula (I-3); STR4 or a 5- or 6-membered heterocyclicthio or bicycloheterocyclicthio group of a formula (I-4):
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