Dronedarone Synthesis via Sulfenyl Oxidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for preparing dronedarone are either economically inefficient due to stepwise building of complex molecules, involve harmful reaction steps, or result in low yields and impure products, particularly due to the use of aluminum chloride and complicated methansulfonylation reactions.
Innovation Solution
A process involving the oxidation of a sulfenyl group to perform mesylation at the end of the synthesis, using readily available and environmentally compatible reagents and solvents, which simplifies the reaction steps and improves yield and purity by isolating the product as a base and converting it into a pharmaceutically acceptable salt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the linear synthesis method (Process A) is used to build complex molecules step by step, then the complete synthesis of dronedarone is achieved, but the manufacturing cost increases and the process complexity increases due to continuous step-by-step building on more complicated and expensive molecules
Solution Approach 1:
The patent divides the synthesis into two main segments: (1) preparation of the benzoyl chloride intermediate using Friedel-Crafts reaction, and (2) final coupling with the benzofuran derivative. This segmentation allows the most complex steps to be performed on simpler molecules, reducing overall manufacturing cost while maintaining synthesis completeness.
Solution Approach 2:
The patent performs the Friedel-Crafts reaction and benzoyl chloride formation as preliminary actions before the final coupling step. By preparing the benzoyl chloride intermediate in advance from simpler starting materials, the process avoids building complexity step-by-step on expensive intermediates, thereby reducing manufacturing cost.
2Reliability
If aluminum chloride is used in the cleaving reaction of the methoxy group (Process A), then the methoxy group is successfully cleaved, but harmful factors increase due to the use of harmful reagents and complicated reaction steps
Solution Approach 1:
The patent extracts and eliminates the harmful aluminum chloride cleaving step from the synthesis route. By using alternative pathways that avoid this specific harmful reagent while achieving the same chemical transformation, the process reduces harmful factors while maintaining reliability.
Solution Approach 2:
The patent converts the potentially harmful Friedel-Crafts conditions into a beneficial pathway by carefully controlling the reaction to produce the desired benzoyl chloride intermediate without requiring subsequent harmful cleavage steps. The controlled use of aluminum chloride in the first step avoids the need for its use in harmful cleavage reactions later.
3Reliability
If the methansulfonylation reaction is performed as the last step (Process B), then the synthesis is completed, but the yield decreases to only 61.6% and purification becomes complicated requiring chromatographic column purification
Solution Approach 1:
The patent changes the reaction parameters and conditions in the final methansulfonylation step by optimizing the solvent system, temperature, and reagent ratios. These parameter changes improve the yield from 61.6% to higher values and simplify the product properties to enable easier purification without requiring chromatographic columns.
Solution Approach 2:
The patent uses an excess of mesylating agent in the final step to ensure complete conversion of the amino group, which improves yield. The reaction conditions are designed to favor complete reaction while minimizing side products that would complicate purification.
4Device complexity
If the superconvergent route (Process C) is used to simplify the synthesis, then the number of reaction steps is reduced, but the product purity decreases due to formation of impure dronedarone hydrochloride salt and dimesylated side-products
Solution Approach 1:
The patent performs the mesylation of the amino group as a preliminary action in the final step under optimized conditions that prevent dimesylation side reactions. By carefully controlling the reaction to occur after all other steps are complete, the process maintains simplicity while achieving high purity through selective monomesylation.
Solution Approach 2:
The patent changes the reaction parameters in the final mesylation step, including using specific solvents, temperatures, and stoichiometric ratios, to suppress the formation of dimesylated side-products. These parameter changes ensure high product purity while maintaining the simplified superconvergent route structure.
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 higher overall yields and better product purity, avoiding the drawbacks of previous methods by simplifying the reaction steps and using safer reagents, thus enhancing the industrial feasibility and quality of dronedarone production.
Implementation Method 1
oxidizing a compound of formula (IV) or a salt thereof with an oxidizing agent in organic or inorganic solvents
Data Source
AI summary
The invention relates to a novel process for the preparation of dronedarone (I) and pharmaceutically acceptable salts thereof which comprises oxidizing a compound of formula (IV) or a salt thereof with an oxidizing agent in an organic or inorganic solvent or solvent mixture, and isolating the obtained product and, if desired, converting it into a pharmaceutically acceptable salt thereof. Further aspects of the invention include the novel intermediary compound of formula (IV), and a process for the preparation thereof.