Catalyst composition and method for chlorinating aromatic compounds
View Patent ↗Aromatic compounds such as toluene and o-xylene are chlorinated in the presence of a catalyst combination prepared by combining (A) at least one salt comprising a metal selected from the group consisting of a Group 4–12 metal, a lanthanide and an actinide; and a counterion; and (B) at least one organic sulfur compound, preferably phenothiazine-N-carbonyl chloride. The catalyst combination may include reaction products of (A) and (B). Under these conditions, production of the p-chloro isomer is optimized. In some embodiments said counterion is an organic counterion derived from at least one acidic organic compound selected from the group consisting of those with an approximate pKa value relative to water of at least about 3.
1. A method for chlorinating an aromatic compound which comprises contacting said aromatic compound with chlorine in the presence of a catalyst combination prepared by combining (A) at least one salt comprising a metal selected from the group consisting of a Group 4–12 metal, lanthanides and actinides; and an organic counterion derived from at least one acidic organic compound selected from the group consisting of those with an approximate pKa value relative to water of at least about 3; and (B) at least one organic sulfur compound.
2. A method according to claim 1 wherein contact takes place in the liquid phase.
3. A method according to claim 1 wherein the temperature is in the range of about 0–100° C.
4. A method according to claim 1 which is conducted with shielding from exposure to ambient light.
5. A method according to claim 1 wherein the aromatic compound is a monocyclic hydrocarbon.
6. A method according to claim 5 wherein the aromatic compound is toluene or o-xylene.
7. A method according to claim 1 wherein the organic compound is a carboxylic acid or a derivative thereof.
8. A method according to claim 1 wherein the organic compound is a 2,4-dione or a derivative thereof.
9. A method according to claim 1 wherein the metal is selected from the group consisting of copper, nickel, cobalt, manganese, molybdenum, zirconium, titanium, vanadium, niobium, palladium or platinum.
10. A method according to claim 1 wherein component A is a copper salt.
11. A method according to claim 1 wherein component A is a nickel salt.
12. A method according to claim 1 wherein component A is a cobalt(II) salt.
13. A method according to claim 1 wherein component A is a manganese(II) salt.
14. A method according to claim 1 wherein component A is cupric acetate, cupric 2,4-pentanedionate, cupric 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, cupric benzoate, nickel acetate, nickel 2,4-pentanedionate, nickel 2,2,6,6-tetramethyl-3,5-heptanedionate, cobalt(II) acetate, cobalt(II) stearate, cobalt(II) 2,4-pentanedionate, manganese(II) acetate, manganese(II) stearate or manganese(II) 2,4-pentanedionate.
15. A method according to claim 1 wherein component A is molybdenum oxide 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate, zirconium 2,4-pentanedionate, zirconium trifluoro-2,4-pentanedionate, titanium oxide 2,4-pentanedionate, vanadium 2,4-pentanedionate, vanadium iodide, niobium 2,2,6,6-tetramethyl-3,5-heptanedionate, niobium iodide, palladium 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate or platinum 2,4-pentanedionate.
16. A method according to claim 1 wherein component B is a dialkyl or diaryl sulfide, dialkyl or diaryl disulfide, alkyl or aryl mercaptan, phenoxathiin, thiophene, dibenzothiophene, thianthrene or phenothiazine.
17. A method according to claim 16 wherein component B is phenothiazine-N-carbonyl chloride, N-trifluoroacetylphenothiazine, 2-chloro-N-trifluoroacetylphenothiazine or 2-trifluoromethyl-N-trifluoroacetylphenothiazine.
18. A method according to claim 1 wherein the proportion of component A is in the range of about 0.005–10.0% by weight based on aromatic compound.
19. A method according to claim 18 wherein the proportion of component A is in the range of about 0.07–3.0% by weight based on aromatic compound.
20. A method according to claim 1 wherein the proportion of component B is in the range of about 0.005–10.0% by weight based on aromatic compound.
21. A method according to claim 20 wherein the proportion of component B is in the range of about 0.01–0.1% by weight based on aromatic compound.
22. A method according to claim 1 wherein the catalyst combination is recovered by removing at least a portion of the other materials by distillation.
23. A method for chlorinating toluene or o-xylene which comprises contacting said toluene or o-xylene with chlorine in the presence of a catalyst combination prepared by combining (A) at least one salt of copper, nickel, cobalt or manganese with a carboxylic acid or 2,4-dione, or derivative thereof; and (B) at least one organic sulfur compound selected from the group consisting of phenothiazine-N-carbonyl chloride, N-trifluoroacetylphenothiazine, 3-chloro-N-trifluoroacetylphenothiazine or 3-trifluoromethyl-N-trifluoroacetylphenothiazine.
24. A method according to claim 23 wherein component A is cupric acetate, cupric 2,4-pentanedionate or cupric 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate.
25. A method according to claim 23 wherein component B is phenothiazine-N-carbonyl chloride.
26. A method according to claim 23 wherein the catalyst combination comprises at least one reaction product of component (A) and component (B).
27. A method according to claim 23 wherein contact takes place in the liquid phase.
28. A method for chlorinating toluene or o-xylene which comprises contacting said toluene or o-xylene with chlorine in the presence of a catalyst combination prepared by combining (A) copper sulfate; and (B) at least one organic sulfur compound.
29. A method according to claim 28 wherein the organic sulfur compound is selected from the group consisting of phenothiazine-N-carbonyl chloride, N-trifluoroacetylphenothiazine, 3-chloro-N-trifluoroacetylphenothiazine and 3-trifluoromethyl-N-trifluoroacetylphenothiazine.
30. A method according to claim 29 wherein component B is phenothiazine-N-carbonyl chloride.
31. A method according to claim 28 wherein the catalyst combination comprises at least one reaction product of component (A) and component (B).
32. A method according to claim 28 wherein contact takes place in the liquid phase.
33. A method for chlorinating an aromatic compound which comprises contacting said aromatic compound with chlorine in the presence of a catalyst combination comprising (1) (A) at least one salt comprising a metal selected from the group consisting of a Group 4–12 metal, lanthanides and actinides; and an organic counterion derived from at least one acidic organic compound selected from the group consisting of those with an approximate pKa value relative to water of at least about 3; and (B) at least one organic sulfur compound, or (2) a reaction product comprising (A) and (B), or (3) the components (A), (B) and a reaction product comprising at least one of (A) or (B).
34. A method according to claim 33 wherein the catalyst combination comprises at least one reaction product of component (A) and component (B).
35. A method according to claim 33 wherein contact takes place in the liquid phase.