Diamine Derivative Synthesis via Staged Acid Addition
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Solution Overview
Problem
The industrial production of compound A, which inhibits activated blood coagulation factor X (FXa), faces significant losses during crystallization and yield variability between production lots, making efficient pharmaceutical production challenging.
Innovation Solution
Reducing the amount of p-toluenesulfonic acid during the dissolution of compound B and increasing it during crystallization of compound A, allowing for stable high yields by adding p-toluenesulfonic acid or its hydrate in divided portions, thereby minimizing decomposition and loss into the mother liquor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If p-toluenesulfonic acid is added in conventional amounts during crystallization, then compound A can be obtained, but significant loss of compound A into the mother liquor occurs and yield varies between production lots
Solution Approach 1:
The patent divides the addition of p-toluenesulfonic acid into two distinct stages: (1) initial addition at less than 1 molar equivalent during dissolution of compound B, and (2) additional addition to reach 1 molar equivalent or more during crystallization of compound A. This segmentation allows optimization of acid amount for each process stage, resolving the contradiction between yield stability and substance loss.
Solution Approach 2:
The patent changes the molar equivalent parameter of p-toluenesulfonic acid dynamically throughout the process: starting with less than 1 molar equivalent during dissolution to prevent decomposition, then increasing to 1 molar equivalent or more during crystallization to maximize recovery and minimize loss into mother liquor, thereby achieving stable high yields.
2Productivity
If p-toluenesulfonic acid is added to dissolve compound B, then compound A can be formed, but decomposition of compound B occurs
Solution Approach 1:
The patent applies partial action by adding less than 1 molar equivalent of p-toluenesulfonic acid during the dissolution stage - sufficient to facilitate the reaction but insufficient to cause significant decomposition of compound B. This partial addition enables productive transformation while minimizing harmful decomposition effects.
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 method stabilizes the yield of compound A at high levels without variability, ensuring consistent and efficient pharmaceutical production by controlling the molar equivalents of p-toluenesulfonic acid throughout the process.
Implementation Method 1
mixing the free form of compound A represented by the following formula (B) (hereinafter, also referred to as compound B) with p-toluenesulfonic acid or p-toluenesulfonic acid monohydrate
Implementation Method 2
followed by crystallization from aqueous ethanol
Data Source
Figure 1~2
AI summary
The present invention provides a method for producing a compound represented by formula (A), the method comprising the steps of: (a) mixing a compound represented by formula (B) with p-toluenesulfonic acid or p-toluenesulfonic acid monohydrate at less than 1 molar equivalent with respect to the compound represented by formula (B) in a solvent under heating; (b) adding additional p-toluenesulfonic acid or p-toluenesulfonic acid monohydrate to the mixed solution under cooling, wherein the additional p-toluenesulfonic acid or p-toluenesulfonic acid monohydrate is added in such an amount that the total molar equivalent thereof with the p-toluenesulfonic acid or p-toluenesulfonic acid monohydrate of step (a) is 1 molar equivalent or more with respect to the compound represented by formula (B) of step (a); and (c) subsequently allowing the mixed solution to crystallize to obtain the compound represented by formula (A).