BOPTA Synthesis via pH-Controlled Carboxymethylation
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Solution Overview
Problem
The existing processes for synthesizing the MRI contrast agent BOPTA are sensitive to pH levels, leading to the formation of undesired byproducts and reduced yields due to the need for continuous pH monitoring, which is impractical and prone to inaccuracies, especially in industrial-scale production.
Innovation Solution
A process that eliminates the need for continuous pH monitoring by adding bromoacetic acid and a base in aliquots at controlled temperatures, allowing the reaction to proceed without pH adjustment, thereby simplifying the procedure and enhancing yield and purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If continuous pH monitoring is implemented to maintain optimal reaction conditions, then the formation of byproducts is reduced, but the process complexity and operational difficulty increase significantly
Solution Approach 1:
The reaction system automatically maintains optimal pH conditions through the inherent buffer capacity of the aqueous medium and the controlled addition of reactants, eliminating the need for external pH monitoring and adjustment equipment. The process self-regulates to prevent byproduct formation without requiring complex control systems.
Solution Approach 2:
The patent removes the pH monitoring and adjustment step from the process entirely, extracting the problematic measurement and control element while retaining the beneficial outcome of optimal pH conditions through simplified reactant addition protocols.
2Measurement precision
If pH electrodes are used to monitor and control the reaction, then reaction precision is improved, but measurement reliability deteriorates due to electrode inaccuracies and maintenance issues
Solution Approach 1:
The patent completely eliminates pH electrodes and measurement devices from the process, removing the source of measurement errors and reliability issues while maintaining optimal reaction conditions through controlled reactant addition and buffer systems.
Solution Approach 2:
The mechanical/electrical pH measurement system is replaced with a chemical control system based on buffer capacity and stoichiometric reactant addition, eliminating the need for electronic sensors and their associated reliability problems.
3Manufacturing precision
If pH adjustment is performed continuously during the reaction, then byproduct formation is minimized, but the production time and operational duration increase
Solution Approach 1:
The reaction medium is pre-prepared with appropriate buffer capacity and ionic strength before reactant addition begins, establishing optimal pH conditions in advance. This preliminary preparation allows the reaction to proceed without continuous adjustment, reducing both time and operational complexity.
Solution Approach 2:
The reaction proceeds continuously with controlled addition of reactants under pre-established optimal conditions, maintaining steady-state pH through the buffer system without interruption for measurement or adjustment, thereby maximizing production efficiency.
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 approach results in high yields and purity of BOPTA, making it suitable for industrial-scale production while avoiding the drawbacks of pH-dependent reactions, such as byproduct formation and yield reduction.
Implementation Method 1
reacting N-[2-[(2-aminoethyl)amino]ethyl]-O-(phenylmethyl)serine of formula (II), or a carboxylate alkaline salt thereof, with a compound of formula (III) XCH2COOH (III) wherein X is a halogen atom
Implementation Method 2
in a first step, one or more aliquots of the compound of formula (III) and of the base are added to an aqueous solution of the compound of formula (II), in a simultaneous, consecutive or alternated way of addition, at a temperature ranging from about 10°C to about 30°C; and b) in a second step, the reaction mixture is warmed up to a temperature ranging from about 30°C to about 60°C
Data Source
AI summary
The present invention refers to a process for preparing a compound of formula (I) through a carboxymethylation reaction occurring in the presence of a suitable alkylating agent and of a base, without the need of monitoring the pH of the reaction environment. The compound of formula (I) is a useful intermediate in the preparation of diagnostic contrast agents for MRI techniques.