Process for producing aromatic primary diamines
The present disclosure relates to a process for the production of aromatic primary amines, by reacting an aromatic dialdehyde with hydrogen and ammonia or an ammonia-liberating compound, in the presence of a hydrogenation catalyst and an amine, wherein the molar ratio of the amine to the aromatic dialdehyde is no less than 1:4 at the start of the reaction.
1. A process for the production of an aromatic primary diamine, the process comprising reacting an aromatic dialdehyde, wherein the aromatic ring is a hydrocarbon ring, with hydrogen and ammonia or an ammonia-liberating compound selected from the group consisting of urea, uric acid, ammonium salts, symmetrical and unsymmetrical carbamates, carbaminates, semicarbazides, semicarbazoles, and aminium salts and organic/inorganic esters thereof, in the presence of a hydrogenation catalyst and an amine, wherein the molar ratio of the amine to the aromatic dialdehyde is no less than 1:4 at the start of the reaction.
2. The process of claim 1 , wherein the amine is selected from a group consisting of methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, benzylamine, cyclohexylamine, ethylene diamine, dimethylamine, diethylamine, diethanolamine, dicyclohexylamine, diallylamine, piperidine, pyrolidine, morpholine, N-methylbenzylamine, dibenzylamine, trimethylamine, triethylamine, triethanolamine, diisopropylethylamine, tricyclohexylamine, triallylamine, benzyldimethylamine, N-methylmorpholine, and N-methyldibenzylamine.
3. The process of claim 1 , wherein the aromatic ring is benzene.
4. The process of claim 1 , wherein the aromatic diamine is m-xylylenediamine and the aromatic dialdehyde is isophthalaldehyde.
5. The process of claim 4 , wherein the amine is a primary amine or a secondary amine.
6. The process of claim 5 , wherein the amine is a primary amine.
7. The process of claim 6 , wherein the primary amine is selected from a group consisting of methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, benzylamine, cyclohexylamine, and ethylene diamine.
8. The process of claim 4 , wherein the amine is a secondary amine selected from the group consisting of dimethylamine, diethylamine, diethanolamine, dicyclohexylamine, diallylamine, piperidine, pyrolidine, morpholine, N-methylbenzylamine, and dibenzylamine.
9. The process of claim 4 , wherein the amine is a tertiary amine selected from a group consisting of trimethylamine, triethylamine, triethanolamine, diisopropylethylamine, tricyclohexylamine, triallylamine, benzyldimethylamine, N-methylmorpholine, and N-methyldibenzylamine.
10. The process of claim 4 , wherein the molar ratio of the amine to isophthalaldehyde is no less than 1:1, at the start of the reaction.
11. The process of claim 4 , wherein the molar ratio of the amine to isophthalaldehyde is no more than 3:1 at the start of the reaction.
12. The process of claim 4 , wherein the molar ratio of isophthalaldehyde to the equivalents of ammonia is in the range of 1:5-1:20.
13. The process of claim 4 , wherein isophthalaldehyde is fed in a manner to ensure that the molar ratio of amine to isophthalaldehyde is in a range of 1:4 to 2:1.
14. The process of claim 4 , wherein the hydrogenation catalyst is Raney copper, Ni/PrO 2 -CeO 2 , or CuNiOx, optionally comprising another metal Zn or Pd.
15. The process of claim 4 , wherein ammonia is used.
16. The process of claim 1 , wherein the aromatic diamine is p-xylylenediamine and the aromatic dialdehyde is terephthalaldehyde.
17. The process of claim 16 , wherein the amine is a primary amine selected from a group consisting of methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, benzylamine, cyclohexylamine, and ethylene diamine.
18. The process of claim 16 , wherein the amine is a secondary amine selected from the group consisting of dimethylamine, diethylamine, diethanolamine, dicyclohexylamine, diallylamine, piperidine, pyrolidine, morpholine, N-methylbenzylamine, and dibenzylamine.
19. The process of claim 16 , wherein the amine is a tertiary amine selected from a group consisting of trimethylamine, triethylamine, triethanolamine, diisopropylethylamine, tricyclohexylamine, triallylamine, benzyldimethylamine, N-methylmorpholine, and N-methyldibenzylamine.
20. The process of claim 16 , wherein the molar ratio of the amine to terephthalaldehyde is no less than 1:1, at the start of the reaction.