Continuous Cyproterone Acetate Synthesis With Online Solvent Switching
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Solution Overview
Problem
Existing synthesis methods for cyproterone acetate involve numerous steps, generate waste, and pose safety risks due to the handling of hazardous materials, resulting in inefficient and environmentally unsustainable production processes.
Innovation Solution
A fully-continuous synthesis method using micromixers, microreactors, and online solvent switching units to catalyze the conversion of androstenedione into cyproterone acetate through a series of controlled reactions, including Δ1-dehydrogenation, alkynylation, Rupe rearrangement, and epoxidation, with enzymatic and chemical catalysts, minimizing intermediate isolation and waste generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional batch synthesis methods are used to produce cyproterone acetate, then the synthesis can be performed with conventional equipment and procedures, but the process involves numerous steps (12-18 steps), generates significant waste, and poses safety risks from hazardous materials handling
Solution Approach 1:
The patent implements continuous flow synthesis where reactions proceed continuously through a series of connected microreactors rather than batch-wise. The continuous flow of reactants through enzymatic reactors, chemical reactors, and extraction units eliminates downtime between batches and maintains constant reaction conditions, thereby improving overall productivity while simplifying the manufacturing process through standardized continuous operation protocols
2Manufacturing precision
If traditional batch synthesis methods are used, then intermediate products can be isolated and purified at each step, but this results in significant waste generation and reduced overall efficiency
Solution Approach 1:
The patent combines multiple operations into integrated continuous flow units. The enzymatic reaction, chemical transformation, and extraction processes occur in sequence within connected microreactors without isolating intermediates. The continuous extraction unit continuously removes products from reaction mixtures, maintaining product purity while eliminating the waste associated with repeated isolation and purification steps
Solution Approach 2:
The patent introduces continuous extraction as an intermediary process between reaction steps. The extraction unit acts as a mediator that continuously separates reaction products from the reaction mixture in flow, allowing the next reaction to proceed without waiting for complete isolation. This maintains manufacturing precision while minimizing substance loss through continuous rather than batch-wise separation
3Adaptability or versatility
If hazardous materials and highly reactive substances are handled in traditional batch processes, then the synthesis can proceed through complex selective transformations, but safety risks increase and environmental compatibility decreases
Solution Approach 1:
The patent segments the synthesis process into discrete modular microreactors, each performing a specific transformation. Hazardous reactions are confined to small-volume individual reactor units rather than large batch vessels. The modular design allows each segment to be optimized for its specific function while isolating hazardous materials to minimal volumes, reducing safety risks and improving environmental compatibility without limiting synthetic versatility
Solution Approach 2:
The patent changes the physical parameters of the synthesis system by transitioning from batch to continuous flow operation. This parameter change allows reactions to proceed under more controlled conditions with better heat and mass transfer, enabling complex selective transformations while reducing the need for large excesses of reagents and minimizing hazardous waste generation through precise stoichiometric control in continuous flow
4Manufacturing precision
If multiple isolation and purification steps are performed in batch synthesis, then product quality can be maintained, but the synthesis time and complexity increase
Solution Approach 1:
The patent maintains product quality through continuous extraction and purification steps that operate throughout the synthesis process rather than requiring repeated batch-wise isolation. The continuous flow extraction units continuously remove products from reaction mixtures, and the final product is purified in a continuous chromatography or crystallization step, eliminating the time losses associated with multiple batch isolation cycles while maintaining manufacturing precision
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
The method achieves high production efficiency with reduced waste and environmental impact, lowering costs and improving safety by integrating continuous-flow biocatalytic and chemical processes.
Implementation Method 1
a 3-ketosteroid-Δ1-dehydrogenase mutant ReM2 and other catalysts are used to catalyze the synthesis of androsta-1,4-diene-3,17-dione from androstenedione
Implementation Method 2
conveying the first mixture to a dynamic tubular reactor and a first microreactor for Δ1-dehydrogenation reaction
Implementation Method 3
pumping, by a first plunger pump, the first feed liquid and the second feed liquid into a first micromixer for mixing to obtain a first mixture
Implementation Method 4
subjecting the first reaction solution to extraction with an extraction solvent in an extraction device followed by phase separation
Implementation Method 5
phase separation in a first online gravity separation column and upper phase removal
Implementation Method 6
concentrating the first lower phase in a first concentration device to obtain a first concentrate
Implementation Method 7
loading the first concentrate onto a first stainless steel column filled with Na2SO4 and SiO2 in a weight ratio of 1:1 for water and impurity removal
Data Source
AI summary
A fully-continuous synthesis method of cyproterone acetate is provided. 4-androstene-3,17-dione is adopted as a starting material. The present disclosure adopts a fully continuous device composed of micromixers, microreactors, online gravity separation units, online solvent switching units, online solvent concentration units and solvent recovery systems connected according to a cyproterone acetate synthesis route. Cyproterone acetate product is synthesized through one enzymatic catalytic reaction, nine chemical reactions and continuous operations. This can realize recovery of dichloromethane, dichloroethane and ethanol, and significantly reduce emission of three wastes. The obtained crude cyproterone acetate is subjected to decolorization, recrystallization, filtration and drying to obtain pure cyproterone acetate with a purity greater than 99%.