| 摘要 |
<p>A process for brominating fluorine- and chlorine-containing halogenated hydrocarbons of formula (I) <IMAGE> (I) wherein R1 represents hydrogen, fluorine, chlorine, bromine, lower alkyl, or at least partially fluorinated lower alkyl; R2 represents hydrogen, fluorine, chlorine, or bromine; and, R3 represents fluorine or perfluorinated lower alkyl, to form the corresponding compounds of formula (II) <IMAGE> (II) wherein R1, R2 and R3 are as defined above is disclosed. According to this process, compounds of formula (I) are reacted in gaseous form at relatively mild reaction conditions, e.g., reaction temperatures of between 100 DEG -500 DEG C. with hydrogen bromide in the presence of a catalyst comprising at least one component selected from the group consisting of (a) active carbon, (b) silica gel, (c) active alumina, and (d) a bromide of an element selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Zn, Cd, Cu, Ag, Al, Tl(I), Pb, Cr, Mn, Fe, Co, Ni, rare earth metals and metals of the platinum group.</p> |
