- NEW AND DIRECT ROUTE TO 5-TRIFLUOROMETHYL-5,6-DIHYDROURACILS BY MEANS OF PALLADIUM COMPLEX CATALYZED "UREIDOCARBONYLATION" OF 2-BROMO-3,3,3-TRIFLUOROPROPENE
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Palladium complex catalyzed carbonylation of 2-bromo-3,3,3-trifluoropropene (2-Br-TFP) with ureas afforded 5-trifluoromethyl-5,6-dihydrouracils in moderate to good yields, which were converted into 5-trifluoromethyluracils in nearly quantitative yields.
- Fuchikami, Takamasa,Ojima, Iwao
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- Preparation method of 5-trifluoromethyl-5,6-dihydrouracil
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The invention provides a preparation method of 5-trifluoromethyl-5,6-dihydrouracil. The preparation method comprises the following steps of: a) performing an addition reaction on 2-trifluoromethyl methylacrylic acid and hydrogen bromide in a solvent to obtain 3-bromo-2-trifluoromethyl methylacrylic acid; b) mixing 3-bromo-2-trifluoromethyl methylacrylic acid obtained in the step a) with ammonia water to perform an ammonolysis reaction to obtain 3-amino-2-trifluoromethyl propionic acid; and c) performing a condensation reaction on the 3-amino-2-trifluoromethyl propionic acid and a cyanate in an acidic solution to obtain 5-trifluoromethyl-5,6-dihydrouracil. The preparation method provided by the invention obtains a target product successively through hydrogen bromide addition, ammonia water ammoniation and cyanate concentration by taking 2-trifluoromethyl methylacrylic acid as an initial raw material. The preparation method is simple in technical route, mild in reaction condition, low in conventional cost of raw materials and suitable for industrial production; and moreover, the preparation method provided by the invention can greatly increase the product yield.
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Paragraph 0066
(2017/08/29)
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- Process for Producing 1-(2'-deoxy-beta-D-erythropentofuranosyl)-5-trifluoromethyluracil Derivatives
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A process for producing 1-(2'-deoxy-β-D-erythro-pentofuranosyl)-5-trifluoromethyluracil derivative of the formula (3) by which the desired compound can be produced easily at a low cost with high selectivity is disclosed. The process according to the present invention comprises (a) reacting 5-trifluoromethyl-5,6-dihydrouracil with alkylsulfoxide in the presence of a halogen and an acid catalyst to obtain 5-trifluoromethyluracil; (b) reacting the obtained 5-trifluoromethyluracil with a silylating agent to obtain 5-trifluoromethyl-2,4-bis(trimethylsilyloxy)pyrimidine of the formula (1) and (c) reacting the obtained 5-trifluoromethyl-2,4-bis(trimethylsilyloxy)pyrimidine with 2-deoxy-α-D-erythro-pentofuranosyl halide derivative of the formula (2) in chloroform solvent in the presence of fluoride ion and in the presence of a copper compound as a catalyst.
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- Production of 5-perfluoroalkyldihydrouracil derivatives
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A process for preparing a 5-perfluoroalkyl-dihydrouracil derivative of the general formula STR1 wherein Rf represents a perfluoroalkyl group, each of R1 and R2 represents a hydrogen atom, or an alkyl, cycloalkyl, aryl, aralkyl or heterocyclic group, and Y is an oxygen or sulfur atom, which comprises (a) reacting a compound of the general formula STR2 wherein X represents a halogen atom or hydroxyl group, with a urea derivative of the general formula STR3 provided that when X is a hydroxyl group and at least one of R1 and R2 is a hydrogen atom, said reaction is carried out in the presence of a condensing agent, or (b) cyclizing a compound of the general formula STR4 and a novel intermediate compound of the above formula (IV).
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