| abstract |
Disclosed is a method of making an α-chloro-α,α-difluoro aromatic compound. An α,α,α-trichloro aromatic compound having general formula (a), (b), (c), (d) or (e) where Y is C or N, R is halogen, R', amino, NHR', NR'2, OR', OCF3, or nitro, R' is alkyl from C1 to C10, n is 1, 2, or 3, and m is 0 to 5, with about 0.7 to about 1.4 equivalents of hydrogen fluoride per chlorine to be replaced, in the presence of about 0.001 to about 1.5 wt%, based on wt% of said a,a,a-trichloro aromatic compound, of a catalyst selected from the group consisting of oxides of Ti, Zr, V, Nb, Ta, Mn, Re, Fe, Ru, Os, Al, Ga, In, Ge, Sn, Sb, and Bi, MoOqXr, (M)pMos+tO3s+4t, (M)pVO3, (M)pVO5, WOqXr, (M)pWs+tO3s+4t, and mixtures thereof, where M is a cation, X is halide, amine, phosphine, carboxylate, or ketone, p is the negative of the valence of the anion times the inverse of the valence of M, q is 0 to 3, r is 0 to 6, and s is 0 to 4, and t is 1 to 5. Yields of 80 % or more were obtained. |