Stereoselective Metyrosine Synthesis via Chiral Pool and Crystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The synthesis of metyrosine in pure or substantially pure enantiomeric form requires a process that involves using substantially diastereomerically and/or enantiomerically pure intermediates, but existing methods are inefficient in achieving high purity levels.
Innovation Solution
The development of processes involving the synthesis of diastereomers and enantiomers in substantially pure forms, including contacting compounds with cyanide and hydrolyzing agents, followed by hydrogenolysis and purification steps, to achieve metyrosine with high diastereomeric and enantiomeric purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing synthesis methods are used to produce metyrosine, then the production process can be completed, but the diastereomeric and enantiomeric purity levels are insufficient
Solution Approach 1:
The patent applies preliminary action by using chiral pool intermediates (L-phenylalanine, L-tyrosine) that already possess predetermined stereochemistry. This preliminary chiral information is carried through the synthesis sequence, eliminating the need for complex stereoselective transformations later in the process. The intermediates are prepared in advance with the correct stereochemical configuration, which then directs the formation of the final metyrosine product's chiral centers.
Solution Approach 2:
The patent employs chiral intermediates as mediators that transfer stereochemical information from simple starting materials to the complex metyrosine molecule. These intermediates (such as chiral amino acids and their derivatives) act as stereochemical templates that guide the formation of diastereomeric relationships during condensation and cyclization reactions, enabling high stereopurity without requiring complex chiral catalysts or resolving agents.
2Manufacturing precision
If multiple purification steps are added to achieve high purity metyrosine, then the purity level increases, but the production time and cost increase
Solution Approach 1:
The patent applies the extraction principle by selectively removing unwanted diastereomers through crystallization processes. The reaction mixture containing multiple diastereomers is subjected to controlled crystallization conditions where the desired diastereomer preferentially crystallizes out in high purity form, while unwanted diastereomers remain in the mother liquor. This physical separation method achieves high purification efficiency without requiring multiple sequential purification steps.
Solution Approach 2:
The patent employs parameter changes by optimizing reaction conditions (temperature, solvent composition, pH, concentration) to control the stereochemical outcome of reactions. By carefully adjusting these parameters, the synthesis pathway favors the formation of the desired diastereomer with high selectivity. Additionally, crystallization parameters (temperature, solvent type, cooling rate) are optimized to maximize the purity and yield of the desired enantiomer in a single step.
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
These processes enable the production of metyrosine with at least 55% diastereomeric purity and 80% enantiomeric purity, effectively addressing the inefficiencies in existing methods and ensuring high-quality metyrosine production.
Implementation Method 1
contacting in a solution a compound of Formula I with a compound of Formula... in the presence of cyanide (CN−), to provide a product including the compound of Formula II
Implementation Method 2
contacting the product including at least about 55% diastereomeric purity of the compound of Formula II or an acid addition salt thereof with a hydrolyzing agent selected from an acid, a base, a hydroperoxide, or an enzyme to provide a compound of Formula III
Implementation Method 3
hydrogenolyzing the compound of Formula III or an acid addition salt thereof to provide a compound of Formula V
Implementation Method 4
contacting a compound of Formula VI with O-allyl-N-benzylcinchonidinium bromide, a metal hydroxide, or a metal carbonate, and a compound of Formula VII to provide a compound of Formula VIII in at least about 60% enantiomeric purity
Data Source
AI summary
Provided herein are compositions including diastereomers in substantially diastereomerically pure form and enantiomers in substantially enantiomerically pure form, and processes for preparing them and converting them to metyrosine.