Dehydroxylation of aminoalcohols to alkyl amines
View Patent ↗The present invention provides a process for producing alkyl amines by dehydroxylation of aminoalcohols. This provides an alternate reaction route for making alkyl amines, such as 2-methylpropane-2-amine and its derivatives.
1. A dehydroxylation process for preparing an alkyl amine from an aminoalcohol comprising:
(A) contacting the aminoalcohol with a dehydroxylation catalyst selected from the group consisting of hydroiodic acid and iodine, in a reaction zone, under hydrogen pressure; and
(B) heating the reaction zone and contents to a reaction temperature between 50° C. and 250° C. to form the alkyl amine.
2. The dehydroxylation process according to claim 1 , wherein said reaction temperature is maintained for a period of time up to 24 hours.
3. The dehydroxylation process according to claim 1 , wherein the dehydroxylation catalyst is hydroiodic acid, and the reaction temperature is between 100° C. and 200° C.
4. The dehydroxylation process according to claim 3 , wherein the aminoalcohol is 2-amino-2-methyl-1-propanol, the reaction temperature is between 120° C. and 200° C., and the alkyl amine produced is 2-methylpropan-2-amine.
5. The dehydroxylation process according to claim 1 , wherein the dehydroxylation catalyst is iodine and the reaction temperature is between 100° C. and 200° C.
6. The dehydroxylation process according to claim 5 , wherein the aminoalcohol is 2-amino-2-methyl-1-propanol and the alkyl amine produced is 2-methylpropan-2-amine.
7. The dehydroxylation process according to claim 1 , wherein the pressure is from 50 psi to 2000 psi.
8. The dehydroxylation process according to claim 1 , wherein the pressure is between 200 psi and 1000 psi.
9. The dehydroxylation process according to claim 1 , wherein the molar ratio of aminoalcohol to dehydroxylation catalyst is 1:10 to 100:1.
10. The dehydroxylation process according to claim 1 , wherein the molar ratio of aminoalcohol to dehydroxylation catalyst is 1:2 to 10:1.
11. The dehydroxylation process according to claim 1 , wherein the process occurs in the presence of a solvent selected from the group consisting of water; acetic acid; propionic acid; straight chain and branched isomers of butyric, pentanoic, and hexanoic acids; and mixtures thereof.
12. The dehydroxylation process according to claim 1 , wherein the reaction temperature is maintained for a period of time up to 6 hours.
13. The dehydroxylation process according to claim 1 , wherein the reaction temperature is between 100° C. and 220° C.
14. The dehydroxylation process according to claim 1 , wherein the aminoalcohol is a C 1 -C 20 aminoalcohol.
15. The dehydroxylation process according to claim 1 , wherein the aminoalcohol is selected from the group consisting of aminoethanol, 1-aminopropanol, 2-aminopropanol, derivatives thereof, and combinations of any two or more thereof.
16. The dehydroxylation process according to claim 1 , wherein the aminoalcohol is 2-amino-2-methyl-1-propanol.
17. A dehydroxylation process for preparing an alkyl amine from an aminopolyol comprising:
(A) contacting the aminopolyol with a dehydroxylation catalyst selected from the group consisting of hydroiodic acid and iodine, in a reaction zone, under hydrogen pressure;
(B) heating the reaction zone and contents to a reaction temperature between 50° C. and 250° C. to form an aminoalcohol; and
(C) continuing to heat the reaction zone and contents to form the alkyl amine.
18. The dehydroxylation process according to claim 17 , wherein the aminopolyol is 2-amino-2-methyl-1,3-propandiol, the aminoalcohol is 2-amino-2-methyl-1-propanol, and the alkyl amine is 2-methylpropan-2-amine.
19. The dehydroxylation process according to claim 17 , wherein the dehydroxylation catalyst is hydroiodic acid and the reaction temperature is between 100° C. and 220° C.
20. A dehydroxylation process for preparing an alkyl amine from an aminoalcohol comprising:
(A) contacting the aminoalcohol with a dehydroxylation catalyst, optionally in the presence of solvent, in a reaction zone under a hydrogen pressure from 50 to 2000 psi, wherein
the dihydroxylation catalyst is selected from the group consisting of hydroiodic acid and iodine;
the molar ratio of aminoalcohol to dehydroxylation catalyst is 1:10 to 100:1; and
(B) heating the reaction zone and contents to a reaction temperature between 100° C. and 220° C. to form the alkyl amine.