Etrasimod Synthesis Using Early Enzymatic Chiral Resolution
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Solution Overview
Problem
Existing processes for preparing etrasimod and related compounds are costly and inefficient at an industrial scale due to the need for chiral separation in the final step, which increases material and waste generation, and the complexity of seeding techniques, leading to lower yields and higher impurity levels.
Innovation Solution
A process involving enantioselective enzymatic hydrolysis of early synthetic intermediates using Thermomyces lanuginosus lipase and Candida antarctica lipase B, followed by hydroxyl deprotection and esterification, to introduce chirality early in the synthesis, reducing material usage and improving yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chiral separation by HPLC is used to obtain enantiomers, then enantiomeric purity is improved, but manufacturing cost and device complexity increase significantly
Solution Approach 1:
The patent introduces a chiral auxiliary (e.g., (S)-1-phenylethylamine) in the early stages of synthesis to control the stereochemistry of the cyclopenta[b]indole core. This preliminary chiral induction eliminates the need for final HPLC separation, as the desired (R)-enantiomer is formed directly with high enantiomeric excess throughout the synthesis pathway.
Solution Approach 2:
The patent removes the HPLC separation step entirely from the synthesis pathway by using chiral auxiliary-based asymmetric synthesis. The chiral information is embedded in the starting materials and carried through all subsequent reactions, extracting the need for complex separation equipment and reducing manufacturing complexity.
2Manufacturing precision
If chiral separation by HPLC is used to obtain enantiomers, then enantiomeric purity is improved, but material consumption and waste generation increase
Solution Approach 1:
The chiral auxiliary is introduced at the beginning of the synthesis and remains attached throughout all reaction steps. This allows the desired enantiomer to be formed selectively from the start, avoiding the 50% material loss that occurs when separating racemic mixtures by HPLC. The auxiliary is later removed in a single deprotection step, recovering the chiral product without wasteful separation.
3Reliability
If seeding techniques are used in the final crystallization step, then product crystallization is improved, but process complexity and impurity introduction increase
Solution Approach 1:
The patent performs enzymatic resolution to obtain enantiomerically pure intermediate (R)-3 before proceeding to crystallization. This preliminary purification ensures that the crystallization step starts with high-purity material, eliminating the need for complex seeding techniques to achieve enantiomeric separation. The seeding process becomes a simple polymorph control step rather than a critical separation operation.
4Manufacturing precision
If enzymatic resolution is performed in the final step, then enantiomeric purity is improved, but overall yield and productivity decrease
Solution Approach 1:
The patent performs asymmetric synthesis using chiral auxiliaries in the early steps to establish the correct stereochemistry before any resolution steps. This preliminary chiral induction ensures that only the desired enantiomer is formed throughout the synthesis, eliminating the need for final enzymatic resolution and avoiding the 50% yield loss associated with resolving racemic mixtures.
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
The process achieves better overall molar and weight yields, reaching up to 59%, and minimizes impurities, making it more cost-effective and suitable for industrial production.
Implementation Method 1
The compound of Formula (V) or a salt or solvate thereof is obtained by enantioselective enzymatic hydrolysis of a compound of Formula (IV) or a salt or solvate thereof in the presence of a lipase selected from Thermomyces lanuginosus lipase and Candida antarctica lipase B
Implementation Method 2
hydroxyl deprotection of the compound of Formula (V) with BBr3
Data Source
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AI summary
The present invention relates to an efficient and industrially applicable process and intermediates for the preparation of etrasimod and related compounds.