- Alkylation of 5-Substituted Tetrazoles with Various Alcohols in 1,2-Dichloroethane in the Presence of BF3·Et2O
-
Abstract: The alkylation of 1H-tetrazole, 5-methyl-1H-tetrazole, and 5-phenyl-1H-tetrazole with primary, secondary, and tertiary alcohols, including benzylic and allylic ones, have been studied in 1,2-dichloroethane in the presence of boron trifluoride–diethyl ether complex. Neither primary nor secondary saturated alcohols alkylated tetrazoles in the given system. Tertiary alcohols such tert-butyl alcohol and adamantan-1-ol reacted with unsubstituted and 5-substituted tetrazoles to give 70–85% of the corresponding 2-alkyl-5-R-tetrazoles with high regioselectivity. The alkylation of 1H-tetrazole with benzyl alcohol afforded 55% of 2-benzyl-2H-tetrazole as the only product. The alkylation of 1H-tetrazole with various allylic alcohols led to the formation of mixtures of 2-alkyl-2H-tetrazoles with isomeric alkyl substituents.
- Egorov, S. A.,Ishchenko, M. A.,Ivanova, V. I.,Prokopovich, Ya. V.
-
-
Read Online
- Chemical synthesis method of 3-isoxazolyl benzyl acetate
-
The invention discloses a chemical synthesis method of 3-isoxazolyl benzyl acetate. The chemical synthesis method comprises the following steps: S1, carrying out addition reaction through butene nitrile and bromine gas and generating 3-amino-5-methylisoxazole in the presence of a hydroxylamine derivative; S2, preparing 3-amino-5-methylisoxazole into diazonium salt under low temperature under the action of catalysis, carrying out substitution reaction on the diazonium salt in a hydrochloric acid environment, substituting amino and preparing 3,5-dimethylisooxazole, carrying out demethylation andpreparing 3-chloromethylisoxazole; and S3, adding 3-chloromethylisoxazole and cuprous cyanide into an organic solvent which is dimethyl sulfoxide, reacting and preparing 3-isooxazole acetonitrile. According to the chemical synthesis method of 3-isoxazolyl benzyl acetate, the raw materials are products obtained by directly cracking petroleum; production is carried out by five steps of addition, catalysis, substitution, hydrolysis and esterification; the reaction is rapid; when 3-chloromethylisoxazole as an intermediate is prepared, the yield reaches up to 75%; the production yield is ensured.
- -
-
Paragraph 0014
(2019/02/04)
-
- A 3 - isoxazole acetate acid animal pen fat chemical synthesis method
-
The invention relates to a chemical synthesis method of 3-isoxazolyl benzyl acetate. According to the invention, chloroacetyl chloride and acetylene are taken as raw materials, the yield of the reaction is increased by addition, condensation, substitution, hydrolysis and esterification steps and an efficient synthesis method is provided for the synthesis of the compound. The synthesis method mainly comprises steps of adding acetylene, chloroacetyl chloride, catalyst aluminum chloride and a solvent tetrahydrofuran into the reaction vessel, reacting, and separating to obtain 1,4-dichloro-3-butenone after the reaction is completed; adding 1,4-dichloro-3-butenone and ammonium sulfate into a methanol or ethanol solvent, controlling the reaction temperature, and reacting to obtain 3-chloromethyl isoxazole; preparing 3-isoxazole acetonitrile; adding 3-isoxazole oxazol-acetonitrile into hydrochloric acid for hydrolyzing to obtain 3-isoxazole acetic acid; adding 3-isoxazole acetic acid and benzyl alcohol into a dichloromethane or trichloromethane solvent, and adding thionyl chloride and a catalyst N, N-dimethyl-formamide for reacting to obtain 3-isoxazolyl benzyl acetate.
- -
-
Paragraph 0021; 0022; 0023; 0034; 0045
(2018/04/01)
-