Isomerization method for cyclohexanediamine
The present invention provides a method for isomerizing a cyclohexanediamine, which simply and highly actively realizes an isomerization reaction of a cyclohexanediamine, without passing through a high-pressure reaction and a complicated multi-stage process. The isomerization method has an isomerization step of isomerizing a cyclohexanediamine in the presence of a compound represented by the following formula (1) and at least one selected from the group consisting of an alkali metal, an alkali metal-containing compound, an alkaline earth metal or an alkaline earth metal-containing compound. wherein R 1 and R 2 each independently represent a hydrogen atom or a monovalent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group and an acyl group (R 1 and R 2 may mutually bind to form a ring); R 3 represents a hydrogen atom and an n-valent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group; and n represents, an integer of 1 to 10.
1. A method for isomerizing a cyclohexanediamine, comprising:
isomerizing the cyclohexanediamine in the presence of an imine compound represented by formula (1) and
at least one selected from the group consisting of an alkali metal, an alkali metal-containing compound, an alkaline earth metal and an alkaline earth metal-containing compound:
wherein R 1 and R 2 each independently represent a hydrogen atom or a monovalent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group and an acyl group, wherein R 1 and R 2 may mutually bond to form a ring; R 3 represents a hydrogen atom or an n-valent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group; and n represents an integer of 1 to 10.
2. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein the substituted or unsubstituted hydrocarbon group represented by each of R 1 and R 2 comprises a monovalent group selected from the group consisting of a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted alicyclic hydrocarbon group and a substituted or unsubstituted aromatic hydrocarbon group; and
the substituted or unsubstituted hydrocarbon group represented by R 3 comprises an n-valent group selected from the group consisting of a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted alicyclic hydrocarbon group and a substituted or unsubstituted aromatic hydrocarbon group.
3. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein the imine compound comprises a compound represented by formula (2) and/or a compound represented by formula (3):
wherein in formula (2), R 1 and R 2 each independently represent a hydrogen atom or a monovalent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group and an acyl group, wherein R 1 and R 2 may mutually bond to form a ring;
wherein in formula (3), R 1 and R 2 each independently represent a hydrogen atom or a monovalent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group and an acyl group, wherein R 1 and R 2 may mutually bond to form a ring.
4. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein the imine compound comprises a compound represented by formula (2a) and/or a compound represented by formula (3a):
wherein in formula (2a), R 1 and R 2 each independently represent a hydrogen atom or a monovalent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group and an acyl group, wherein R 1 and R 2 may mutually bond to form a ring,
wherein in formula (3a), R 1 and R 2 each independently represent a hydrogen atom or a monovalent group selected from the group consisting of a substituted or unsubstituted hydrocarbon group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group and an acyl group, wherein R 1 and R 2 may mutually bond to form a ring.
5. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein the imine compound is obtained by dehydration condensation between a primary amine and an aldehyde and/or a ketone.
6. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein the imine compound is obtained by dehydration condensation between the cyclohexanediamine and an aldehyde and/or a ketone.
7. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein the cyclohexanediamine is 1,4-cyclohexanediamine.
8. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein the alkali metal-containing compound comprises at least one selected from the group consisting of an alkali metal hydride and an alkali metal amide.
9. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein an isomerization reaction temperature in the isomerizing is 100 to 140° C.
10. The method for isomerizing a cyclohexanediamine according to claim 9 , wherein, in the isomerizing, a solvent having a boiling point equal to or lower than the isomerization reaction temperature is used.
11. The method for isomerizing a cyclohexanediamine according to claim 1 , wherein, in the isomerizing, bubbling is performed by an inert gas.