- Photochemistry of CF3(CH2)2CHO in air: UV absorption cross sections between 230 and 340 nm and photolysis quantum yields at 308 nm
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This work constitutes the first study on the photochemical degradation process of CF3(CH2)2CHO. Firstly, the wavelength and temperature dependence of the UV absorption cross sections, σλ, was determined. The n → π* electronic transition band of CO chromophore was characterized between 230 and 340 nm in the 269-323 K range. A hyperchromic effect was observed in the structured part of the band when the temperature decreases. Maximum σ λ = 283, 291 nm at 323 K is ca. 22% larger than those at 269 K. Secondly, the pulsed laser photolysis of a stationary mixture of CF 3(CH2)2CHO/cyclohexane (OH-scavenger)/air or N2 was carried out at 308 nm. On-line Fourier transform infrared (FTIR) spectroscopy was employed to monitor the decay of CF3(CH 2)2CHO and to obtain the photolysis quantum yield, Φλ = 308 nm, as a function of total pressure (20.5-760 Torr). A slight curvature in the Stern-Volmer plot was observed at pressures lower than 75 Torr. At high pressures, the pressure dependence of Φλ = 308 nm can be described by a Stern-Volmer relationship. Photodissociation of CF3(CH2)2CHO at 308 nm can produce HCO and CF3(CH2)2 radicals (1a), CF3CH2CH3 and CO (1b) and CF3(CH2)2CO radicals and H atoms (1c). HCO radicals are rapidly converted into CO in the presence of O2. Formation of CF3CH2CHO and CF3CH 2CH2OH evidences the importance of secondary chemistry involving CF3(CH2)2 radicals formed in channel (1a). Further photodegradation of CF3CH2CHO yields mainly CF3CHO. Small quantities of HC(O)OH were also detected. CF 3(CH2)2C(O)OH was only observed in the absence of OH-scavenger, implying that formation of CF3(CH2) 2CO radicals in channel (1c) is not an important photolysis pathway. Consequently, photodissociation of CF3(CH2)2CHO in the actinic region is a source of shorter fluorinated oxygenated compounds, but it is not expected to be a source of fluorinated acids.
- Anti?olo,Jiménez,Albaladejo
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- Preparation method of 3, 3, 3-trifluoropropanol
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The invention discloses a preparation method of 3, 3, 3-trifluoropropanol, and belongs to the field of organic synthesis. The preparation method comprises the following steps: (1) under the action of an initiator, reacting chlorotrifluoroethane and magnesium in a polar solvent to prepare a Grignard reagent CF3CH2MgCl solution; (2) reacting the Grignard reagent CF3CH2MgCl solution with formaldehyde in a polar solvent to obtain a CF3CH2CH2OMgCl solution, wherein the polar solvent does not contain water; and (3) adding an acid into the CF3CH2CH2OMgCl solution, and carrying out hydrolysis to prepare the 3, 3, 3-trifluoropropanol. According to the method, chlorotrifluoroethane is used as a raw material to prepare the 3, 3, 3-trifluoropropanol, and the preparation raw materials are cheap and easy to obtain, the cost is low, the preparation process is safe, and the reaction conditions are mild; and the yield of the 3, 3, 3-trifluoropropanol is high, byproducts are few, and the solvent can be recycled.
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Paragraph 0040-0093; 0113
(2021/11/19)
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- METHOD FOR PRODUCING 3,3,3-TRIFLUOROPROPANOL
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PROBLEM TO BE SOLVED: To provide a method for producing 3,3,3-trifluoropropanol efficiently on an industrial scale. SOLUTION: 3,3,3-trifluoropropanol is produced by the reaction between benzyl vinyl ether represented by the following formula [where R is a phenyl group, or a phenyl group having a substituent represented by R1 (where R1 is an alkyl group, an alkoxy group, a halogen atom or a nitro group)] and hydrogen (H2) in the presence of a palladium catalyst. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0051-0052
(2018/01/09)
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- Method for preparing 3,3,3-trifluoro propanol
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The invention discloses a method for preparing 3,3,3-trifluoro propanol. The method comprises the following steps: adding 2-bromine-3,3,3-trifluoro propanol, a solvent, a catalyst and an acid-binding agent into a high pressure kettle, pressurizing to be 2-8Mpa, and heating to be 70-100 DEGC to react for 2-6 hours, thereby obtaining 3,3,3-trifluoro propanol. The total yield is 85.7% calculated from 3,3,3-trifluoro propene. The method is mainly used for preparing 3,3,3-trifluoro propanol.
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Paragraph 0022; 0023
(2016/12/01)
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- Investigation of the factors controlling the regioselectivity of the hydroboration of fluoroolefins
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Either Markovnikov or anti-Markovnikov regioselectivity can be achieved at will during the hydroboration-oxidation of perfluoroalkyl(aryl)ethylenes by varying the hydroborating agent.
- Ramachandran, P. Veeraraghavan,Jennings, Michael P.
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p. 386 - 387
(2007/10/03)
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- Novel Nucleophilic Trifluoromethylation of Vicinal Diol Cyclic Sulfates
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(Matrix Presented) A novel method for highly regioselective and stereospecific nucleophilic trifluoromethylation of vicinal diol cyclic sulfates, using the reagent derived from reduction of trifluoromethyl iodide by tetrakis(dimethylamino)ethylene (TDAE), is presented.
- Takechi, Naoto,Ait-Mohand, Samia,Medebielle, Maurice,Dolbier Jr., William R.
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p. 4671 - 4672
(2007/10/03)
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- Markovnikov hydroboration of perfluoroalkylethylenes
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A Markovnikov regioselectivity of 92% or higher is achieved in the hydroboration of a series of perfluoroalkylethylenes and 2',3',4',5',6'- pentafluorostyrene with dichloro- and dibromoborane to provide the corresponding (fluoroalkyl)dihaloboranes (see reaction).
- Brown, Herbert C.,Chen, Guang-Ming,Jennings, Michael P.,Ramachandran, P. Veeraraghavan
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p. 2052 - 2054
(2007/10/03)
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- Critical role of catalysts and boranes for controlling the regioselectivity in the rhodium-catalyzed hydroboration of fluoroolefins
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(formula presented) Catalytic hydroboration of perfluoroalkylethylenes (RFCH=CH2) with cationic and neutral rhodium complexes allows for selective access to either regioisomeric alcohol after hydroboration with catechol- and pinacolboranes, followed by oxidation with alkaline hydrogen peroxide.
- Ramachandran, P. Veeraraghavan,Jennings, Michael P.,Brown, Herbert C.
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p. 1399 - 1402
(2008/02/09)
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