- Method for preparing 1, 1 and 1 -trifluoro -2 -methyl -2 - propanol
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The invention discloses a method for preparing 1, 1 and 1 -trifluoro -2 -methyl -2 - propanol. To the method, methyl magnesium halide Grignard reagent is prepared from halogenated methane as a raw material in ether solvents, 1, 1 and 1 - trifluoroacetone are reacted in the presence of a catalyst to obtain 1, 1, 1 -trifluoro -2 -methyl -2 -propanol. The method has the advantages of easily available raw materials, convenience in post-treatment and purification, simplicity in operation, relatively low cost, high yield and the like.
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Paragraph 0039
(2021/12/07)
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- Design, synthesis and biological evaluation of novel fluorinated docetaxel analogues
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A series of novel fluorinated docetaxel analogues have been synthesized and evaluated in vitro and in vivo. Incorporated one, two or three fluorine atom(s) either at both meta position on C-2 benzolate and 3′-N-tert-butyloxyl group or only at 3′-N-tert-butyloxyl group has resulted in potent analogues which have comparable or superior in vitro and in vivo cytotoxicity to docetaxel. Among them, compounds 14d and 14e have displayed more potent cytotoxicity than docetaxel both in human cancer cell line SK-OV-3 in vitro and in human non-small cell lung cancer A549 xenografts in vivo. Preliminary data show that compound 14a has reduced acute animal toxicity in mice compared with docetaxel.
- Lu, Hong-Fu,Sun, Xun,Xu, Liang,Lou, Li-Guang,Lin, Guo-Qiang
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experimental part
p. 482 - 491
(2009/09/06)
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- Trifluoromethylation of carbonyl compounds with sodium trifluoroacetate
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In the presence of copper(I) iodide as catalyst, a variety of carbonyl compounds, such as aldehydes, ketones and acid anhydrous, could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields, and a possible mechanism was proposed to explain the roles of catalyst and solvent in the reaction system.
- Chang, Ying,Cai, Chun
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p. 937 - 940
(2007/10/03)
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- Cesium fluoride catalyzed trifluoromethylation of esters, aldehydes, and ketones with (trifluoromethyl)trimethylsilane
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The low reactivity of carboxylic esters toward (trifluoromethyl)trimethylsilane (TMS-CF3) was investigated. A universal cesium fluoride catalyzed procedure for nucleophilic trifluoromethylation was developed. At room temperature (25 °C, with catalytic amounts of cesium fluoride, carboxylic esters were found to react to give the silyl ether intermediates, which afforded the trifluoromethyl ketones after hydrolysis. Sulfonic, sulfinic, and selenic esters also show good reactivity, giving novel trifluoromethylated compounds. The trifluoromethylation method was also applied to aldehydes and ketones, which were transformed to trifluoromethyl silyl ether intermediates and afforded trifluoromethylated alcohols in excellent yields after acid hydrolysis. Ethylene glycol dimethyl ether was used as solvent for solid or high boiling substrates, and benzonitrile was used for the low boiling substrates.
- Singh, Rajendra P.,Cao, Ganfeng,Kirchmeier, Robert L.,Shreeve, Jean'ne M.
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p. 2873 - 2876
(2007/10/03)
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- Mechanistic Studies of Gas-Phase Negative Ion Unimolecular Decompositions. Alkoxide Anions
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The unimolecular decompositions of 15 gas-phase alkoxide negative ions have been studied by infrared multiple photon photochemical activation in an ion cyclotron resonance spectrometer.Upon pulsed CO2 laser irradiation, alkoxide anions undergo elimination of neutral molecules (e.g., alkanes RH) to yield enolate anions.The observed reactivity patterns and kinetic isotope effects further establish a stepwise decomposition mechanism involving initial heterolytic cleavage to an intermediate anion-ketone complex followed by proton transfer to give the ultimate products.A relative order of leaving group propensities CF3 > Ph > H > t-Bu > Me > i-Pr > Et was observed.The apparent anomalous reactivity order for the alkyl groups can be rationalized by invoking a change in mechanism to one involving an intermediate in which an electron is not bound specifically by the eliminated alkyl group for R + t-Bu, i-Pr, and Et: either a radical-ketone radical anion complex produced by homolytic cleavage or an anionic cluster.This order also leads to the conclusion that methane elimination from alkoxide anions proceeds via the pathway involving heterolytic cleavage.The results of this study have implications for bimolecular ion-molecule reaction dynamics, since the photochemically generated intermediates are also intermediates in bimolecular proton transfer reactions.
- Tumas, William,Foster, Robert F.,Brauman, John I.
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p. 2714 - 2722
(2007/10/02)
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- CH3(.) vs. CF3(.): Relative Rates of Formation from β-Scission
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The relative rates of formation of CH3(.) and CF3(.) from β-scission reactions of trifluoro-t-butoxy radical (1) have been measured to be about 10:1 by thermolysing both trifluoro-t-butyl hypochlorite (4) and bis(trifluoro-t-butyl) peroxydicarbonate (14) in CCl4 at 160 and 140 deg C.
- Jiang, Xi-Kui,Li, Xing-Ya,Wang, Ke-Yang
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p. 745 - 746
(2007/10/02)
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- Solvolysis of 2-(Trifluoromethyl)-2-propyl Trifluoromethanesulfonate. Solvent, Salt, and β-Deuterium Isotope Effects. Sucstituent Effect of a Strongly Deactivating Group and Rate-Limiting Solvent-Assisted Elimination
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Solvolysis rates of 2-(trifluoromethyl)-2-propyl trifluoromethanesulfonate (2c) in a variety of solvents did not show a correlation with rates for 2-adamantyl tosylate in the same solvents.The effect of added salts on the rates of 2c and 2-propyl tosylate in 80percent EtOH was very similar, with significant rate increases for nucleophilic/basic salts.Methyl CD3 isotope effects on the rate of 2c in three solvents showed average values k(d0)/k(d3) = 1.78 and k(d0)/k(d6) = 3.80.The initial observed product from 2c was CF3C(CH3)=CH2 (4) in all cases.The rate ratio k(i-PrOTf)/k(2c) ranges from a high of 4 x 106 in TFA to a low of 1.5 x 104 in EtOH and shows a high degree of destabilization of a cationic transition state by the CF3 group.The results are interpreted in terms of rate-limiting solvent or salt attack on an intimate ion pair formed from 2c.The observed average product ratio CF3C(CD3)=CH2/CF3C(CH3)=CD2 of 1.9 from 2c-d3 in CF3CO2D, HFIP, and CD3CO2D is consistent with this conclusion.
- Jansen, Michael P.,Koshy, Kalavelil M.,Mangru, Nevindra N.,Tidwell, Thomas T.
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p. 3863 - 3867
(2007/10/02)
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