Tofacitinib Synthesis via Segmented Deprotection and Recrystallization
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Solution Overview
Problem
Existing processes for preparing tofacitinib are time-consuming, laborious, and produce products with impurities, requiring multiple purification steps which reduce yield.
Innovation Solution
A novel process involving reactions and deprotection steps to form compounds of Formula IVA, V-I, and V-II, followed by purification through recrystallization of tofacitinib monocitrate from a mixture of acetonitrile and water, to obtain pure tofacitinib and its salts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing processes are used for preparing tofacitinib, then the preparation can be performed, but the process is time-consuming and laborious
Solution Approach 1:
The synthesis process is divided into distinct modular stages: condensation reaction to form intermediate, deprotection step, and crystallization. Each stage is optimized independently with specific reagents and conditions, allowing parallel development and scaling of individual steps to improve overall productivity.
Solution Approach 2:
Protecting groups (trityl, benzyl) are strategically introduced in advance to prevent unwanted side reactions during subsequent synthesis steps. The deprotection step is planned and executed at the optimal time to yield the final product with minimal additional purification requirements, streamlining the overall process.
2Manufacturing precision
If existing processes are used for preparing tofacitinib, then the product can be obtained, but impurities are generated requiring multiple purification steps
Solution Approach 1:
The protecting groups (trityl, benzyl) that initially seem to add complexity actually serve to direct regioselectivity and prevent side reactions, thereby reducing impurity formation. The deliberate introduction of these groups followed by controlled deprotection converts a potential complexity issue into a benefit for achieving high purity with fewer purification steps.
Solution Approach 2:
The crystallization step utilizes precise control of solvent composition (acetonitrile-water mixture), temperature, and pH to optimize product purification. By adjusting these parameters, the process achieves high purity tofacitinib in a single crystallization step rather than requiring multiple sequential purifications.
3Manufacturing precision
If multiple purification steps are performed to remove impurities, then product purity is improved, but product yield is reduced
Solution Approach 1:
Impurities are selectively removed through targeted extraction steps using specific solvents and pH conditions. The protecting group chemistry enables impurities to be separated into different phases or forms, allowing their removal without significant loss of the desired product, thereby maintaining both high purity and yield.
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 simplifies the preparation of tofacitinib, reduces impurity issues, and enhances product yield by streamlining the purification process, resulting in a more efficient and effective method for producing tofacitinib and its salts.
Implementation Method 1
reacting a compound of Formula IVA with a compound of Formula III-I to form a compound of Formula V-I
Implementation Method 2
deprotecting the compound of Formula V-I obtained in step (a) to form a compound of Formula V-I wherein at least one of R or R1 is hydrogen
Implementation Method 3
purification through recrystallization of tofacitinib monocitrate from a mixture of acetonitrile and water
Data Source
AI summary
The present invention relates to process for the preparation of tofacitinib and intermediates thereof.