Process for preparing a mixture of methyl- or ethyl-substituted primary anilines

Abstract

A process is disclosed for preparing an isomeric mixture of a monomethyl-, dimethyl- or monoethyl-substituted aniline consisting essentially of contacting at least one of said anilines with a specified zeolite at about 250°-500° C. and about 10 kPa-10 MPa of pressure.

The invention being claimed is: 
     
       1. A process for preparing an isomeric mixture of an alkyl-substituted aniline having the formula ##STR5## wherein R is a methyl or ethyl group, n is 1 or 2 when R is methyl, and n is 1 when R is ethyl, the process consisting essentially of contacting at least one compound of formula I with a zeolite catalyst at a temperature of from about 250° to 500° C. and at a pressure of from about 10 kPa to 10 MPa, said zeolite catalyst .[.having pores with dimensions of from about 0.5 nm to less than about 0.7 nm and having cages with dimensions no greater than about 0.7 nm.]. .Iadd.selected from the group consisting of HZSM-4, HZSM-5, HZSM-8, HZSM-11, HZSM-34, HZSM-35, HZSM-47, H-β, H-L, NaZSM-5, NaZSM-12, H-mordenite and H-offretite and a mixture thereof when n=1 and selected from the group consisting of HZSM-5, HZSM-8, HZSM-11, and HZSM-34 and a mixture thereof when n=2.Iaddend., with the proviso that when R is methyl and n=2 the formula I anilines can only be 2,4-, 2,5- and 3,4-dimethylanilines. 
     
     
       2. A process according to claim 1 wherein contacting with the catalyst is performed for a time of from about 0.1 second to 10 hrs. 
     
     
       3. A process according to claim 2 wherein .Iadd.n=1 and .Iaddend.the catalyst is selected from the group consisting of HZSM-4, HZSM-5, HZSM-8, HZSM-11, HZSM-34, HZSM-35, HZSM-47, H-β, H-L, NaZSM-5, NaZSM-12, H-mordenite and H-offretite or a mixture of any of the foregoing. 
     
     
       4. A process according to claim 3 wherein the catalyst is HZSM-5. 
     
     
       5. A process according to claim 3 wherein the catalyst is HZSM-8. 
     
     
       6. A process according to claim 3 wherein the contacting is performed in the presence of a solvent. 
     
     
       7. A process according to claim 6 wherein the solvent is aniline. 
     
     
       8. A process according to claim 3 wherein R is a methyl group. .[.9. A process according to claim 8 wherein n is 1..]. .[.10. A process according 
     
     
        to claim 8 wherein n is 2..]. 11. A process according to claim 8 wherein 
     
     
        the product is approximately an equilibrium mixture of isomers. 12. A process according to claim 8 wherein the catalyst is HZSM-5 or HZSM-8. 
     
     
            A process according to claim 12 wherein the catalyst is HZSM-5. 14. A process according to claim 12 wherein the catalyst is HZSM-8. .Iadd.15. A process according to claim 2 wherein n=2 and the catalyst is selected from the group consisting of HZSM-5, HZM-8, HZSM-11 and HZSM-34. .Iaddend. .Iadd.16. A process according to claim 15 wherein the catalyst is HZSM-5. .Iaddend. .Iadd.17. A process according to claim 15 wherein the catalyst is HZSM-8. .Iaddend.