Glycine-Proline Cyclization Process Without Chromatography
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Solution Overview
Problem
Existing methods for synthesizing cyclic glycine-proline compounds are not scalable and efficient, particularly in the scalable synthesis of cyclic glycine-proline compounds, such as cG-2-AllylP, which are required for clinical investigation and manufacturing, due to low yields and the use of chromatography that is not viable in large-scale quantities.
Innovation Solution
A scalable and efficient process for synthesizing bicyclic glycine-proline compounds, including cG-2-AllylP, through a base-initiated cyclization reaction, avoiding the need for chromatography and using amide coupling and acid-catalyzed esterification conditions to achieve high purity and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If flash chromatography is used for purification at each reaction step, then purification quality is improved, but scalability and productivity deteriorate due to inability to handle large-scale quantities
Solution Approach 1:
The patent removes the flash chromatography purification step from the synthesis pathway entirely. Instead of purifying at each intermediate step, the process uses a telescoped approach where reactions are performed sequentially without isolation, and a single final purification step is applied to the crude mixture after the complete four-step sequence, enabling scalable production while maintaining adequate purity.
Solution Approach 2:
The patent combines multiple reaction steps and purification operations into a telescoped sequence where intermediates are not isolated. The four reaction steps (oxazolidinone formation, alkylation, ring-opening, and cyclization) are performed in sequence with carryover of crude materials, merging what were previously separate purified steps into an integrated process that maintains productivity while achieving final purification.
2Productivity
If TFA and Et3N are used for cyclisation step, then cyclisation reaction proceeds, but a mixture of salts is formed making isolation difficult
Solution Approach 1:
The patent changes the chemical parameters of the cyclization step by using different reagents (sodium methoxide instead of TFA/Et3N) and different solvent conditions (methanol instead of dichloromethane). These parameter changes result in the formation of a single clean salt product that can be easily isolated by filtration, eliminating the mixture of salts problem while maintaining cyclization efficiency.
Solution Approach 2:
The patent converts the previously problematic salt formation issue into a beneficial outcome. By using sodium methoxide as the base, the reaction produces a single well-defined salt that precipitates cleanly and can be easily filtered, transforming what was previously an isolation difficulty into a simplifying feature of the process.
3Manufacturing precision
If four reaction steps are performed with purification at each step, then each step can be optimized, but total yield deteriorates to approximately 6%
Solution Approach 1:
The patent implements continuous synthesis where the four reaction steps proceed in an unbroken sequence without interruption for purification. Each reaction mixture is carried forward to the next step, maintaining continuous useful action throughout the synthesis pathway. This eliminates the cumulative yield loss from multiple purification steps while allowing each individual reaction to be optimized for its specific transformation.
Solution Approach 2:
The patent performs preliminary reactions in sequence without waiting for purification of previous steps. The oxazolidinone formation, alkylation, ring-opening, and cyclization are executed as preliminary actions leading to the final product, with the understanding that final purification will handle any carryover impurities. This approach maintains high overall yield while still achieving the necessary purity.
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 enables the production of bicyclic glycine-proline compounds with improved yields and purity, suitable for clinical development, by using a base-initiated cyclization reaction and amide coupling, overcoming the limitations of previous methods.
Implementation Method 1
a base initiated cyclisation reaction of a compound of Formula 2 to form the compound of Formula 1
Implementation Method 2
reacting a compound of Formula 4 or salt thereof with a compound of Formula 5 under amide coupling conditions
Implementation Method 3
reacting a compound of Formula 6 or salt thereof under acid-catalysed esterification conditions
Data Source
AI summary
The present disclosure generally relates to a process for the synthesis of bicyclic glycine-proline compounds, and monocyclic glycine-proline intermediates thereof. In particular, the present disclosure also relates to a process for the synthesis of cyclic G-2-AllylP and its analogues. The present disclosure also relates to a process for the synthesis of optionally protected monocyclic glycine-proline intermediates. The present disclosure also relates to a process for the synthesis of esterified glycine-proline intermediates. The present disclosure also relates to compounds prepared by the processes and the use of such compounds to prepare compositions and to treat disorders.