2-bromo-2-chloro-l, 1,1 -trifluoroethane

Costas, M. Perez- sas, S. Dohnal, V. Fenclova, D. Excess molar enthalpies of binary mixtures of 2-bromo-2-chloro-l, 1,1-trifluoroethane (halothane) with oxygenated and hydrocarbon solvents Thermochim. Acta 1993,213... 

Haloalkanes can be regarded as substituted alkanes in which one or more of the hydrogen atoms is replaced by a halogen atom. They are named in a similar fashion to branched-chain alkanes with the halogen atoms treated like branches. For example, the anaesthetic halothane has the structure shown in the diagram and is called 2-bromo-2-chloro-l,l, 1-trifluoroethane. 

Halothane (2-Bromo-2-chloro-1,1,1 -trifluoroethane) (HCBD) see Hexachloro-1,3-butadiene (HCFC-141B) see 1,1-Dichloro-l-fluoroethane (HDDA) see 1,6-Hexanediol diacrylate (HEMA) see 2-Hydroxyethyl methacrylate n-Heptane... 

A nonconventional synthesis of the known inhalation anaesthetic, 2-bromo-2 chloro-l,l,l-trifluoroethane (Halothane), based on the reaction of ethyl 1,2 di bromo-1,2-dicliloroethyl ether with anhydrous hydrogen fluoride and sulfur tetrafluoride, has been patented The reaction presumably involves cleavage of the ether linkage, followed by fluorination of the intermediate bromochloroacetyl halide with sulfur tetrafluoride, ethyl halides are the by-products [2] (equation 2)... 

Complex formation equilibria in binary mixtures of chloroform with dipropyl ether (PE), diisopropyl ether (IPE), methyl tert-butyl ether(MBE), tetrahydrofuran (THE), 1,4-dioxane (DOX), acetone (AC), and methyl acetate (MA) have been analyzed in detail. The complex formation equilibria in chloroform mixtures was compared to those previously examined for halothane (2-bromo-2-chloro-l,l,l-trifluoroethane) mixed with the same oxygenated solvents. It was found that the H-bonds formed by halothane are stronger than those formed by chloroform (Dohnal and Costas, 1996). 

In addition to MAK values, which are for healthy persons capable of earning a normal living, the DFG publication20 includes so-called BAT values (biological tolerance limits) for substances which show additional biological effects. These define maximum concentrations of a substance, or its metabolites, normally in the blood or urine of an employee. Only one fluorinated chemical was included in 1997. 2-bromo-2-chloro-l,l,l-trifluoroethane = Halo-thane, CAS-No. 151-67-7, with a BAT value for trifluoroacetic acid (its toxic metabolite) of 25 mg - L 1 in human blood determined after exposure/shift. 

Bromo-2-chloro-l.l,l-trifluoroethane (3) is obtained from 1.2-dibromo-1.2-dichloro-l-ethoxyethane with sulfur tetrafluoride/hydrogen fluoride at 100 C in an autoclave. ... 

BBromo-2-chloro-1,1,2-trifluoroethane 2-Bromo-2-cbloro-1.l.1-lriHuoroelbane... 

Much work has been done to develop catalyst systems that optimize yield and reduce side reactions. The reaction has an induction period, which depends on the temperature and the amount of catalyst.8 An early patent from Bayer claims that a nearly quantitative yield can be achieved in the conversion of l,2-dibromo-1-chloro-l.2.2-trifluoroethane(5) into 1,1-di-bromo-l-chloro-2,2.2-trifluoroethane (6) when aluminum tribromide is used in 2-broino-2-chloro-1,1,1-trifluoroethane (4) as solvent.12 A Japanese patent26 describes the activation of aluminum trichloride or alumina by pretreatinent with l,L2-trichloro-l,2,2-trifluoroethane (1) (see discussion of compound 19, vide infra). A later patent claims that aluminum trichloride and tribromide can also be activated by complexing with 1,1-dichloro- (CF3CFC12) and 1,1-dibromo-1,2,2,2-tetrafluoroethane (CF3CFBr2), respectively 2 an example of the latter is shown in the formation of bromofluoroalkane 10. 

Preparation. Thermal elimination of HCl from l-chloro-l,l-difluoroethane (HCFC-142b) [75-68-3] is the principal industrial route to VDF covered by numerous patents (8—19). Dehydrohalogenation of l-bromo-l,l-difluoroethane (20), or 1,1,1-trifluoroethane (HFC-143a) (21—25), or dehalogenation of l,2-dichloro-l,l-difluoroethane (26—28) are investigated alternative routes (see Fluorine compounds, organic-fluorinated aliphatic compounds). 

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