1,1,1-TRI FLUOROETHANE

Molybdenum hexafluoride, in the presence of boron trifluonde, reacts with acetic acid and haloacetic acids at 130-160 °C to give respectively, 1,1,1 tri fluoroethane and 1,1 1 trifluorohaloetlianes in 60-89% yields [2d0, 241] Prolonged treatment of pyridine mono and dicarboxylic acids with an excess of molybdenum hexafluoride at elevated temperatures provides the respective mono-and bis(trifluoromethyl)pyridines in good yields [241] (equation 127)... 

Tsuda, Takehide Shibanuma, Takashi. Preparation of difluoromethane and 1,1,1-tri-fluoroethane. JP 08217704A 19960827 (1996). 

If hydrogen fluoride can be eliminated in two different ways, it is always the more acidic hydrogen that leaves preferentially. Hydrogen beta to fluorine is significantly more acidic than when alpha to fluorine.30 Consequently, hydrogen fluoride is eliminated from 1,1,2-tri-fluoroethane (24) to form 1,2-difluoroethene [(EjZ)-25],23 and from l//,2//-hexafluoropropane (26) to preferentially give 1 f/-pentafluoroprop-l-ene (27).24-25... 

Property Methylene Chloride Perchloro- ethylene 1,1,1-Tri- chloroethane Trichloro- ethylene Trichlorotri- fluoroethane... 

Unlike petroleum hydrocarbons, organic compounds in general followed a different evolutionary path. Chlorinated solvents are a common group of organic compounds, and are also the most frequently encountered contaminant in groundwater. Common industrial chemicals that are characterized as chlorinated solvents include trichloro-ethene (TCE), 1,1,1-trichloroethane (TCA), tetrachloroethene (PCE) or perchloro-ethylene, chlorofluorocarbon (Freon)-113 (i.e., 1,1,2-trichloroethane or 1,2,2-tri-fluoroethane), and methylene chloride. In 1997, the EPA reported the presence of TCE and PCE in 852 of 945 groundwater supply systems throughout the United States and in 771 of 1420 Superfund sites. 

Young, Fukuhara and Bigelow repeated the vapor-phase reaction of fluorine/nitrogen mixtures with ethane, obtaining pentafluoroethane. 1,1.2,2-tetrafluoroethane. and 1,1,2-tri-fluoroethane, together with products of C — C bond fission. 

The equimolar mixture of bromine trifluoride and bromine can be employed for the bro-mofluorination of fluorine-free alkcncs such as (Z)- and( )-l,2-dichloroethene, methyl acrylate and its a-substituted derivatives.1 The reactions are carried out in l,l,2-trichoro-l,2,2-tri-fluoroethane (CFC-113) using a 25-35 % excess of bromine trifluoridc/ bromine. The direction of the bromine monofluoride" addition to multiple bonds in the esters, much as in other electrophilic reactions, depends on the electronic nature of the substituent R. 

The rate constants, kadd, obtained from the LFP experiments for addition of the perfluoro-n-alkyl radicals to the various alkenes in l,2,2-trichloro-l,l,2-tri-fluoroethane (FI 13) are given in Table 7. It can be seen that such radicals are much more reactive than their hydrocarbon counterparts, particularly in additions to electron-rich alkenes, with n-C3F7 adding to 1-hexene 30000 times faster, and to styrene 350 times faster than an n-alkyl radical [ 114,115]. 

Both enantiomers of enflurane [2-chloro-l-(difluoromethoxy)-l,l,2-tri-fluoroethane], isoflurane [2-chloro-2(difluoromethoxy)-1,1,1 -trifluoroeth-ane] and desflurane [2-(difluoromethoxy)-l,l,l,2-tetrafluoroethane] were used as chiral analytes. 

Tetrahaloethy lene/ HF 2.2- Dichloro-],U-tri-fluoroethane, 2-chloro- 1.1.1.2- tetra-fluoroe thane Metal fluoride on y-aluinina 250-450 °C, gaseous phase 30... 

An adapted version of the Sagami-synthesis (Reaction scheme 65) allows the use of the interesting 3,3-dimethylpentenic ester IIL If one chlorine atom in carbonte-trachloride is substituted by CF3 or CH3, or if 1,1-dibromotetrafluoroethane is used, the radical addition to this olefinic bond is still feasible. As in the case of 1,1,1-trichloroethane, more drastic conditions are required. l,l,l-trichloro-2-tri-fluoroethane, on the other hand, behaves almost normally, thus providing an efficient starting point to produce the desired acid as shown in Reaction scheme 144, particularly if the 1,3-cyclo-elimination is carried out with potassium carbonate in dimethylacetamide at 140 °C, giving predominantly the cis-Z-isomer [411]. 

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