Aripiprazole Lauroxil Synthesis via Anhydrous Esterification
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Solution Overview
Problem
Current processes for preparing aripiprazole lauroxil have low yields and are not cost-effective or easily scalable to an industrial level, with impurities present in the final product that complicate purification.
Innovation Solution
A process involving the reaction of a compound of formula (II) with lauric acid and a carboxyl activating agent in the presence of a solvent, optionally with a base, is used to produce aripiprazole lauroxil, where the reaction is conducted in the absence of water or with minimal water content to achieve higher conversion and purity, and the intermediate compound is converted into aripiprazole lauroxil using standard esterification methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional processes are used to prepare aripiprazole lauroxil, then the synthesis can be performed with existing methods, but the yields are very low and purification is complicated due to impurities
Solution Approach 1:
The patent changes the water content parameter in the reaction system from conventional aqueous conditions to anhydrous or low-water conditions. This parameter change fundamentally alters the reaction pathway and intermediate stability, leading to both higher yields and improved purity by preventing hydrolysis side reactions and facilitating easier purification of the final product
Solution Approach 2:
The patent introduces a specific intermediate compound (7-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butoxy)-3,4-dihydroquinolin-2(1H)-one) as a key mediator in the synthesis pathway. This intermediate serves as a stable platform that enables subsequent conversion to aripiprazole lauroxil with high efficiency and minimal impurity formation, resolving the contradiction between yield and purity
2Productivity
If conventional esterification methods are used, then the process can proceed with standard reagents, but the conversion into aripiprazole lauroxil is only 65% and 25% aripiprazole remains as impurity
Solution Approach 1:
The patent applies parameter changes by conducting the esterification reaction in the absence of water or with minimal water content (≤1 wt%). This dramatic change in moisture parameter drives the reaction to near-complete conversion while preventing the formation of aripiprazole impurity, achieving both high productivity and low harmful byproducts
Solution Approach 2:
The patent employs preliminary anti-action by pre-forming the intermediate compound under anhydrous conditions before esterification. This preliminary step prevents the formation of hydrolysis products and ensures that subsequent esterification proceeds with maximum conversion and minimal impurity generation
3Ease of manufacture
If aqueous formaldehyde is used in the intermediate step, then the reaction can be performed with readily available reagents, but 25% aripiprazole is found in the final product with only 65% conversion
Solution Approach 1:
The patent changes the physical state parameter of the formaldehyde reagent from aqueous solution to anhydrous form (paraformaldehyde). This parameter change, while requiring slightly different handling, enables complete conversion of aripiprazole to the intermediate compound and eliminates aripiprazole impurity in the final product, dramatically improving productivity
4Productivity
If the process is scaled up to industrial level, then production volume increases, but conventional processes are not cost-effective and difficult to scale
Solution Approach 1:
The patent applies parameter changes by eliminating water from the reaction system and using readily available reagents under mild conditions. These changes simplify the process for industrial scaling by removing the need for complex water removal equipment and enabling straightforward process optimization for large-volume production with consistent high yields and purity
Solution Approach 2:
The patent employs cheap, readily available reagents and solvents that can be easily handled and disposed of, making the process economically viable for industrial scale-up. The use of common bases and standard esterification reagents eliminates the need for expensive specialized chemicals, improving ease of manufacture at industrial volume
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 aripiprazole lauroxil with significantly higher yields and purity, making it easier to purify and scale up industrially, while minimizing impurities and allowing for efficient production.
Implementation Method 1
reacting a compound of formula (II) with lauric acid and a carboxyl activating agent in the presence of a suitable solvent and, optionally, in the presence of an appropriate base, to obtain aripiprazole lauroxil
Implementation Method 2
reacting aripiprazole of formula (III), or a hydrate thereof such as aripiprazole monohydrate, with paraformaldehyde in the presence of a suitable organic solvent and a suitable base, wherein the process is carried out either in the absence of water
Data Source
AI summary
It is provided a process for the preparation of aripiprazole lauroxil that comprises reacting 1-(hydroxymethyl) aripiprazole with lauric acid in the presence of a suitable solvent and a carboxyl activating agent in the presence of a suitable solvent and, optionally, in the presence of an appropriate base. 1-(Hydroxymethyl) aripiprazole can be prepared by reacting aripiprazol or an hydrate thereof with paraformaldehyde in the presence of a suitable organic solvent and a suitable base, wherein the reaction is carried out without the addition of water as a solvent to the reaction mixture. Additionally, (7-(4-(4-(2,3-dichlorophenyl)piperazin-1-yl)butoxy)-3,4-dihydro-2-oxoquinolin-1(2H)-yl)methyl formate is provided as a reference standard.