- Method for preparing 3,4'-dichlorodiphenyl ether from difenoconazole isomer
-
The invention relates to a method for preparing 3,4'-dichlorodiphenyl ether from a difenoconazole isomer. The preparation method comprises the steps of hydrolysis, a haloform reaction, a decarboxylation reaction and the like. According to the preparation method disclosed by the invention, 3,4'-dichlorodiphenyl ether can be efficiently prepared from the difenoconazole isomer. The method not only can effectively reduce solid wastes, turn the waste into the wealth, reduce production cost and improve the economic benefits, but also can be applied to synthesis of other drug intermediates.
- -
-
Paragraph 0084; 0090-0093; 0099-0102; 0108-0110
(2021/04/28)
-
- Triazole compound containing dioxolame and preparation method of intermediate of triazole compound
-
The invention relates to a preparation method of a dioxolane-containing triazole compound and an intermediate thereof, and the method comprises the following steps: reacting a compound shown as a formula (V) with a compound shown as a formula (IV) in the presence of Lewis acid to prepare a compound shown as a formula (III); reacting the compound shown in the formula (III) with a compound shown in the formula (II) to prepare the compound shown in the formula (I). According to the technical scheme, a triazole group is introduced into 1H-1, 2, 4-triazole-1-acetic acid, generation of an isomer 1, 3, 4-triazole byproduct is avoided, the reaction yield is increased, and the method has the advantages of being simple and convenient in process route, few in reaction step, simple in process, low in production cost, environmentally friendly, green and safe; the post-treatment of the product only needs a simple solvent crystallization process, a nitric acid salifying method and a high-temperature distillation method do not need to be adopted, the requirements on equipment are reduced and the cost is reduced under the condition of improving the yield and content of the product, and the method is suitable for industrial production.
- -
-
Paragraph 0035
(2021/09/04)
-
- Production device of 3, 4-dichlorodiphenyl ether
-
The utility model relates to a production device of 3, 4-dichlorodiphenyl ether, which comprises a parachlorophenol head tank, an etherification synthesis kettle, a centrifugal mother liquor tank, an etherification desolventizing kettle, an etherification distillation kettle and a 3, 4-dichlorodiphenyl ether receiving tank which are sequentially connected, and the upper part of the etherification synthesis kettle is sequentially connected with a condenser and an etherification separated water receiving tank; a centrifugal transfer pump and a potassium chloride centrifugal machine are sequentially arranged on a connecting pipeline of the etherification synthesis kettle and the centrifugal mother liquor tank, the upper part of the etherification desolventizing kettle is sequentially connected with a condenser and an m-dichlorobenzene receiving tank, and the upper part of the etherification distillation kettle is sequentially connected with a condenser, a 3, 4-dichlorodiphenyl ether front fraction tank and a 3, 4-dichlorodiphenyl ether receiving tank. The production device disclosed by the utility model is simple in overall structure, all equipment is convenient to operate, and by arranging the condensing device, the centrifugal transfer pump, the centrifugal pump and the like, the production process is optimized, the production efficiency is improved, and the effects of low energy consumption and cost saving are realized.
- -
-
Paragraph 0005; 0028; 0036-0038
(2021/07/01)
-
- A method for utilizing microwave catalytic synthesis of 3, 4' - two chlorine two ether method
-
The invention discloses a method for catalytically synthesizing 3,4'-dichlorodiphenyl ether by using microwaves, which comprises the following steps: mixing m-dichlorobenzene, parachlorophenol, an alkali and an organic solvent, and meanwhile, adding a copper salt as a catalyst, wherein the m-dichlorobenzene:parachlorophenol:alkali:copper salt mole ratio is (1-10):(1-10):(1-2):(0.001-0.1), and the organic solvent accounts for 5-20 wt% of the total materials; and under the catalytic actions of microwaves with the power of 200-1000W, stirring the mixture to react at 60-130 DEG C under atmospheric pressure for 1-3 hours. The microwave-organic solvent combination is utilized to catalytically synthesize the 3,4'-dichlorodiphenyl ether, so that the reaction temperature is lowered. The reaction selectivity is 96%, and the yield can reach 93%. Meanwhile, the catalyst can be recycled. The microwave-assisted synthesis has the characteristics of high reaction speed, high yield, high safety, environment friendliness, fewer side reactions and the like, is easy to operate, enhances the production efficiency, and lowers the production cost.
- -
-
Paragraph 0024-0044
(2017/08/24)
-
- Copper-mediated synthesis of mono- and dichlorinated diaryl ethers
-
An efficient synthesis of polychlorinated diphenyl ethers (PCDEs) using the Cu(OAc)2-catalyzed Chan-Lam coupling reaction is described. A library of all possible mono- and dichlorinated diphenyl ether congeners was prepared and characterized using MS, 1H, and 13C NMR spectroscopy, and Kovats retention indices. Our approach, using the optimized reaction conditions (i.e., reaction temperature, oxidizing atmosphere and base), significantly improves and simplifies the process compared to previously reported syntheses.
- ?ermák, Jan K.,Církva, Vladimír
-
supporting information
p. 4185 - 4188
(2014/07/22)
-
- Synthesis, Structure Verification, and Chromatographic Relative Retention Times for Polychlorinated Diphenyl Ethers
-
Fifty-four polychlorinated diphenyl ether (PCDEs) congeners were synthesized, and their structures were confirmed by mass spectrometry and proton magnetic resonance spectroscopy. The gas chromatographic relative retention times (RRT) for the PCDEs were determined relative to a reference standard, -tetrachlorobiphenyl (PCB 77) on the fused silica capillary columns of SE-54 and OV-1701. The retention times for PCDEs increased with the increasing number of vicinal chlorines within a series of isomers. The chlorine substitution patterns of PCDEs were used to develop a method for predicting RRTs for congeners that were not synthesized.
- Nevalainen, Tapio,Koistinen, Jaana,Nurmela, Pirjo
-
p. 1341 - 1347
(2007/10/03)
-
- Process for preparing chlorinated diphenyl ethers
-
The invention relates to a novel process for preparing chlorodiphenyl ethers of the formula I STR1 in which R is hydrogen or chlorine, which comprises heating a material of the formula III STR2 in which X is one equivalent of an alkali metal or alkaline earth metal ion and R is as defined above, in an excess of a dichlorobenzene of the formula II STR3 in the presence of a copper catalyst and of an aprotic solvent as cocatalyst at temperatures of 120°-220° C.
- -
-
-
