- Environment-friendly 2-ethyl-4-methylimidazole synthesis method
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The invention discloses an environment-friendly synthesis method of 2-ethyl-4-methylimidazole, and belongs to the technical field of organic synthesis. The method comprises: generating aminopropyl propionamide at a temperature of 80 DEG C from low-toxicity methyl propionate and 1,2-diaminopropane according to a proper reaction ratio; carrying out cyclization with water on the aminopropyl propionamide and an aromatic hydrocarbon in the presence of a catalyst to generate 2-ethyl-4-methylimidazoline; and dehydrogenating the 2-ethyl-4-methylimidazoline at a temperature of 120-40 DEG C in the presence of a pd/c catalyst to prepare the 2-ethyl-4-methylimidazole. According to the invention, the 2-ethyl-4-methylimidazole is prepared by using the method, so that the use of high-toxicity propionitrile, high-pollution aldehyde and ammonia and high-risk Raney nickel catalysts capable of burning in the presence of air are avoided, no waste ammonia is generated in the production process, and the method belongs to an environment-friendly method for preparing the 2-ethyl-4-methylimidazole.
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Paragraph 0009; 0010
(2020/03/09)
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- Preparation method of 2-ethyl-4-methylimidazole
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The invention discloses a preparation method of 2-ethyl-4-methylimidazole. The preparation method comprises steps as follows: diamine and propionitrile have a cyclization reaction sequentially at the temperature of 80-110 DEG C and 120-140 DEG C under the catalysis of a catalyst; a product after the cyclization reaction has a dehydrogenation reaction through raney nickel at the temperature of 170-200 DEG C, and 2-ethyl-4-methylimidazole is obtained. The preparation method has the advantages that 2-ethyl-4-methylimidazole is prepared with a substep method, the process cost is reduced, the reaction process is optimized, the operation is simple and convenient, the pollution is reduced, and the reaction yield is high.
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Paragraph 0019; 0029; 0031; 0032; 0033
(2016/10/10)
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- Tetrasubstituted imidazoles
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A compound of the formula STR1 wherein the substituents are defined in the specification useful for the treatment of cardiovascular disorders.
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- Method of preventing abnormal stimulation of AT1 and AT2 receptors
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Products of formula (1), wherein R1 is particularly STR1 alkyl, alkylthio or alkoxy; R2 is particularly halogen, --S--R, --O--R or --C(OH)(R)--COOH, where R is alkyl or alkenyl; R3 is particularly carboxy, acyl, halogen, alkyl, alkenyl or alkylthio; and R4 is particularly --(CH2)m1 --COOR4, --(CH2)m1 --CONHR14, --(CH2)m1 --CN, --SO2 --NH--SO2 --R14, 13 NH--SO2 --R14, --PO3 R14, or --NH--SO2 --CF3, where m1 is 0-4 and R14 is hydrogen, alkyl or alkenyl; are useful for preparing pharmaceutical compositions for treating disorders resulting from abnormal stimulation of angiotensin II receptors AT1 and AT2.
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- CATALYTIC SYNTHESIS OF C-ALKYLIMIDAZOLES OVER PLATINUM-ALUMINA CATALYSTS
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The synthesis of C-alkylimidazoles from 1,2-diamines and carboxylic acids over bifunctional platinum-alumina catalysts has been studied.It has been shown that this method is effective for the synthesis of 2-alkyl and 2,4-dialkylimidazoles including imidazoles with long-chain alkyls.The effect of the reaction temperature, space velocity of the flow of the raw materials, and dilution by hydrogen on the yield of product has been examined for the example of the synthesis of 2-methylimidazole from ethylenediamine and acetic acid, and the stability of the catalyst in continuous reaction cycles with intermediate oxidative regeneration has been studied.The composition of the accompanying products has been established and a mechanism proposed for their formation.Keywords: bifunctional catalyst, platinum-alumina catalyst, alkylimidazoles, 2-methylimidazole.
- Gitis, K. M.,Neumoeva, G. E.,Raevskaya, N. I.,Arutyunyants, G. A.,Isagulyants, G. V.
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p. 728 - 734
(2007/10/02)
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