Low pressure process for the manufacture of 2-(aminomethyl)-1-cyclopentylamine
Disclosed herein is a process for the manufacture of 2-(aminomethyl)-1-cyclopentylamine by low-pressure hydrogenation of 1-amino-2-cyano-1-cyclopentene using a combination catalyst system of nickel with palladium on carbon, or a single palladium-doped Raney-type catalyst.
1. A process for preparing 2-(aminomethyl)-1-cyclopentylamine, said process comprising:
(i) preparing an activated catalyst by combining a suitable solvent and a catalyst system in a vessel purged with an inert gas, pressurized with hydrogen to about 50-500 psi at a temperature of about 25° C. to about 50° C., wherein said catalyst system comprises either nickel and palladium, wherein said palladium is supported on carbon, or palladium-doped Raney type nickel
(ii) contacting said activated catalyst with 1-amino-2-cyano-1-cyclopentene, at least an equimolar portion of anhydrous ammonia, and a solution of an aqueous inorganic base selected from the group consisting of sodium hydroxide, lithium hydroxide and potassium hydroxide;
(iii) pressurizing the vessel by raising the temperature of the vessel to a temperature of about 50° C. to about 150° C. and a pressure of hydrogen of about from 500 psi to about 1500 psi and maintaining said temperature and pressure for a time sufficient to obtain crude 2-(aminomethyl)-1-cyclopentylamine;
(iv) separating crude 2-(aminomethyl)-1-cyclopentylamine product; and
(v) optionally, purifying crude 2-(aminomethyl)-1-cyclopentylamine to obtain purer 2-(aminomethyl)-1-cyclopentylamine.
2. The process of 1 wherein said 1-amino-2-cyano-1-cyclopentene of step (ii) is obtained by contacting adiponitrile with a molar equivalent amount of a sterically hindered based in a non-polar, aromatic solvent to produce 1-amino-2-cyano-1-cyclopentene; and isolating the 1-amino-2-cyano-1-cyclopentene product of step.
3. The process of claim 2 wherein the 1-amino-2-cyano-1-cyclopentene of step (ii) is dissolved in dioxane/water solvent.
4. The process of claim 1 wherein said process is run in a batch mode and wherein said process further comprises, after step (i) and before step (ii) reducing the temperature and pressure to ambient conditions.
5. The process according to claims 1 or 3 wherein the 2-(aminomethyl)-1-cyclopentylamine is purified by distillation.
6. The process of claims 1 or 3 wherein said suitable solvent is water, an aprotic polar organic solvent, a combination of aprotic polar organic solvents, or a combination of aprotic polar organic solvent and water.
7. The process of claim 6 wherein said suitable solvent is a dioxane/water solution.