Enantiomerically Pure Amines via Crystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The separation of enantiomerically pure amines, such as amino and thio protected hydroxy-mercapto-cyclohexyl amines, is burdensome and often requires sophisticated and expensive chromatographic methods, which are not feasible on a technical scale for pharmaceutical applications where one isomer may have significantly different properties than the other.
Innovation Solution
A process for producing enantiomerically and regioisomerically pure amino and thio protected hydroxy-mercapto-cyclohexyl amines through oxiran ring opening, followed by crystallization, which allows for the isolation of these compounds in high yield and purity without the need for cumbersome chromatography, using sulfur donating groups and appropriate solvents like toluene or chlorobenzene.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chromatography is used for isomeric separation, then enantiomerically pure amines can be obtained, but the process becomes burdensome, expensive, and not feasible on technical scale
Solution Approach 1:
The invention changes the physical-chemical parameters of the system by forming diastereomeric salts through reaction with chiral resolving agents. This transformation converts enantiomers (which have identical physical properties) into diastereomers (which have different solubilities and crystallization behaviors), enabling separation through simple filtration and crystallization rather than complex chromatography
Solution Approach 2:
Chiral resolving agents act as intermediaries that temporarily bind to the enantiomers to form diastereomeric salts. These intermediaries enable separation by creating compounds with different physical properties, after which the original enantiomers can be recovered by treating the separated salts with base
2Manufacturing precision
If conventional separation methods are used, then isomeric purity can be achieved, but production cost and time increase significantly
Solution Approach 1:
The invention exploits phase transitions, specifically crystallization from solution, to separate diastereomeric salts. By controlling temperature and solvent conditions, one diastereomer crystallizes preferentially while the other remains in solution, enabling efficient separation through filtration rather than time-consuming chromatographic methods
Solution Approach 2:
The separation process is segmented into distinct steps: formation of diastereomeric salts, filtration to separate crystallized material from mother liquor, and recovery of pure enantiomers. This segmentation allows each step to be optimized independently and facilitates scaling to industrial production
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 method significantly enhances the yield and chemical purity of enantiomerically pure compounds, achieving yields of ≥30% and chemical purities of ≥95%, facilitating their production on an industrial scale and improving regioselectivity and stability, particularly when using trifluoroacetyl protection.
Implementation Method 1
interesting enantiomerically and regioisomerically pure compounds may be isolated, e.g. in solid, such as in crystalline form, from the reaction mixture
Data Source
AI summary
A compound of formulawherein PROT is an amine protecting group and PROT′ is hydrogen; or PROT and PROT′ together with the nitrogen atom to which they are attached form a heterocyclic ring as an amine protecting group, and PROT″ is a thiol protecting group, processes for its production, intermediates in their production and production of intermediates in stereoisomerically pure form, and their use for the production of pharmaceutically active compounds.