Fragment Coupling Synthesis for Pasireotide Purity
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Solution Overview
Problem
Current methods for synthesizing Pasireotide, such as solid phase sequential synthesis, face challenges with low yield and purity, particularly in achieving the desired peptide in sufficient quantities and high purity greater than 99.0% by HPLC.
Innovation Solution
A fragment-based synthesis process involving the coupling of protected peptide fragments, followed by cyclization and deprotection, to obtain Pasireotide with purity greater than 99.0% by HPLC, utilizing suitable protecting groups and coupling reagents like HBTU and DIPEA, and purification techniques like Reverse Phase HPLC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If solid phase sequential synthesis is used to prepare Pasireotide, then the synthesis process can be automated, but the yield and purity are insufficient
Solution Approach 1:
The patent divides the Pasireotide synthesis into separate protected fragments that are synthesized independently through solid phase sequential synthesis, then coupled together in solution phase. This segmentation allows each fragment to be purified individually before final assembly, resolving the contradiction between automation and purity by enabling intermediary purification steps that would be difficult in a fully sequential automated process.
2Extent of automation
If solid phase sequential synthesis is used to prepare Pasireotide, then the synthesis process can be automated, but the yield is low
Solution Approach 1:
By segmenting the synthesis into fragment preparation and coupling stages, the patent enables optimization of each stage independently. The solution phase coupling of protected fragments allows for better yield optimization through controlled reaction conditions and intermediary purification, resolving the contradiction between automation and productivity.
Solution Approach 2:
The patent performs preliminary synthesis and purification of protected fragments before final coupling. This preliminary action ensures that only high-purity fragments are coupled, preventing carryover of impurities that would reduce overall yield and requiring re-purification steps.
3Ease of manufacture
If sequential addition of amino acids is used, then the synthesis follows a straightforward protocol, but intermediary purification is not possible
Solution Approach 1:
The patent segments the synthesis into distinct phases: solid phase synthesis of fragments with protecting groups, isolation/purification of these fragments, and final solution phase coupling. This segmentation explicitly enables intermediary purification while maintaining protocol clarity through well-defined stages, resolving the contradiction between ease of manufacture and manufacturing precision.
4Ease of manufacture
If conventional synthesis methods are used, then the process is well-established, but the purity achieves less than 99.0% by HPLC
Solution Approach 1:
The patent uses segmentation with protected fragments synthesized separately and purified individually, then coupled in solution phase with controlled deprotection. This approach achieves greater than 99.0% purity by preventing impurity accumulation that occurs in conventional sequential synthesis, while remaining based on well-established peptide synthesis and coupling methodologies.
Solution Approach 2:
The patent employs protecting groups as intermediaries that allow selective manipulation and purification of peptide fragments at different stages. These protecting groups enable intermediary purification steps and controlled deprotection, achieving high final purity while using conventional synthesis building blocks and techniques.
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 results in a high-yield, high-purity Pasireotide di-aspartate with purity greater than 99.5% by HPLC, providing an industrially scalable and robust method for its preparation.
Implementation Method 1
coupling of the fragments of step (a) to obtain peptide of formula (IV)
Implementation Method 2
cyclizing the peptide of formula (V), followed by deprotection to obtain Pasireotide
Implementation Method 3
converting the peptide of formula (IV) to peptide of formula (V)
Implementation Method 4
purification techniques like Reverse Phase HPLC
Data Source
AI summary
The present invention relates to a process for the preparation of Pasireotide of formula (I) and its acid addition salts. More particularly the present invention is directed to a process for the synthesis of Pasireotide of formula (I) having purity greater than 99.0 % by HPLC using fragment coupling.