Cyclic Amine Conversion to Diamines via Catalyst
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Solution Overview
Problem
Current processes for converting aliphatic cyclic amines to aliphatic diamines are hindered by the formation of side products like bicyclic amines, which result in lower yields of desired 1,3-bis(aminomethyl)cyclohexane, with no effective means to convert these by-products into desired diamine products.
Innovation Solution
A process involving the selection of cyclic amines such as 3-azabicyclo[3.3.1]nonane and azabicyclo[3.3.1]non-2-ene, contacted with ammonia and hydrogen in the presence of heterogeneous metal-based catalyst systems at specific temperature and pressure ranges, followed by distillation steps to separate and convert these amines into aliphatic diamines like 1,3-bis(aminomethyl)cyclohexane or hexamethylene diamine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional processes are used to convert aliphatic cyclic amines to aliphatic diamines, then the desired diamine products are formed, but side products like bicyclic amines are generated which lower the yield
Solution Approach 1:
The patent converts the harmful side product (bicyclic amine) into a beneficial product (desired diamine) by applying reductive amination conditions. The bicyclic amine is transformed into 1,3-bis(aminomethyl)cyclohexane through contact with ammonia and hydrogen in the presence of a catalyst, thereby converting waste into valuable product and improving overall yield.
Solution Approach 2:
The patent employs specific reaction parameters including temperature range (80-250°C), pressure conditions (1-3500 psig), and catalyst selection to optimize the conversion of bicyclic amine to desired diamine. These parameter changes enable selective transformation of the side product while minimizing further unwanted reactions.
2Productivity
If there are no conversion processes for bicyclic amine by-products, then the desired diamine yield remains limited, but implementing new conversion processes adds process complexity
Solution Approach 1:
The patent merges the conversion of bicyclic amine by-product with the main reductive amination process. Both the formation of desired diamine from aldehyde and the conversion of bicyclic amine side product occur in the same reactor system under identical conditions, eliminating the need for separate conversion equipment and reducing overall process complexity.
Solution Approach 2:
The catalyst system and reaction conditions serve multiple functions: they catalyze both the primary reductive amination of aldehyde to diamine and the secondary conversion of bicyclic amine by-product to the same diamine product. This multi-functionality simplifies the process by using a single reaction system for multiple transformation goals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process effectively converts aliphatic cyclic amines into aliphatic diamines with improved yields, utilizing specific catalysts and conditions to manage by-product conversion and separation, enhancing the production of valuable diamines like 1,3-bis(aminomethyl)cyclohexane and hexamethylene diamine.
Implementation Method 1
contacting said one or more cyclic amines with ammonia and hydrogen, optionally water, and optionally one or more solvents in the presence of one or more heterogeneous metal based catalyst systems
Implementation Method 2
removing at least a portion of said portion of ammonia, said portion of hydrogen, or mixture thereof from said product mixture via distillation
Data Source
AI summary
The instant invention is a process for the conversion of aliphatic cyclic amines to aliphatic diamines. The process for conversion of aliphatic cyclic amines to aliphatic diamines comprises the steps of: (1) selecting one or more cyclic amines; (2) contacting said one or more cyclic amines with ammonia and hydrogen, optionally water, and optionally one or more solvents in the presence of one or more heterogeneous metal based catalyst systems at a temperature in the range of from 120° C to about 250° C and a pressure in the range of from 700 to 3500 psig for a period in the range of at least one hour or more in one or more reactor systems; (3) forming a product mixture comprising one or more aliphatic diamine, optionally a portion of said one or more cyclic amines, optionally a portion of said ammonia, optionally a portion of said hydrogen, optionally water, and optionally a portion of said one or more solvents; (4) removing said product mixture from the reactor system; (5) removing at least a portion of said portion of ammonia, said portion of hydrogen, or mixture thereof from said product mixture via distillation; (6) removing at least a portion of said portion of water via distillation; (7) removing at least a portion of said portion of one or more optional solvents via distillation; (8) removing at least a portion of said portion of one or more cyclic amines; (9) thereby separating said one or more aliphatic diamines from said product mixture; and (10) thereby converting said one or more cyclic amines to one or more aliphatic diamines.