SGLT-2 Inhibitor Synthesis via Convergent Coupling
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Solution Overview
Problem
Current methods for synthesizing SGLT-2 inhibitors like empagliflozin and dapagliflozin face challenges such as lack of stereo selectivity, long synthetic routes, use of hazardous and expensive reagents, complex work-up procedures, and inefficient protection of hydroxyl groups, making them uneconomical and unsuitable for large-scale production.
Innovation Solution
A novel, convergent synthesis process involving coupling of specific compounds with tetrahydrofuran-3-ol and subsequent hydrolysis, followed by reduction, to produce empagliflozin and dapagliflozin with high enantiomeric purity and yield, using safer and cheaper reagents, and forming amorphous solid dispersions with pharmaceutically acceptable polymers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional multi-step synthesis methods are used for SGLT-2 inhibitors, then complete chemical transformation is achieved, but the synthetic route becomes long and uneconomical for large-scale production
Solution Approach 1:
The synthesis is divided into distinct modular segments: (a) formation of aryl ketone from benzyl chloride, (b) coupling with protected glucopyranose, (c) deprotection to yield final product. Each segment is optimized independently with specific reagents and conditions, allowing parallel development and scaling of individual steps rather than sequential optimization of a long route.
Solution Approach 2:
The glucopyranose unit is pre-protected with acetyl groups before coupling, and the benzyl chloride is pre-functionalized with carbonyl groups. These preliminary preparations enable direct coupling in a single step to form the C-glycoside bond, avoiding the need for multiple intermediate transformation steps in the conventional approach.
2Reliability
If hazardous reagents like boron tribromide are used for demethylation, then complete deprotection is achieved, but safety risks and cost increase
Solution Approach 1:
The patent employs inexpensive, non-hazardous reagents such as aluminum chloride and hydrochloric acid that can be used in large quantities for industrial-scale deprotection without the safety concerns associated with boron tribromide. These reagents are readily available, easy to handle, and their waste streams are more environmentally friendly, making them suitable for disposable use in large-scale production.
Solution Approach 2:
The deprotection conditions are optimized by adjusting parameters such as temperature, solvent system (dichloromethane/methanol), and reagent concentration. The use of aluminum chloride followed by hydrochloric acid treatment provides complete deprotection through controlled hydrolysis, achieving the same result as boron tribromide but under safer, more controllable conditions suitable for industrial manufacture.
3Manufacturing precision
If multiple protection groups are used for hydroxyl groups, then selectivity is improved, but the process complexity and cost increase
Solution Approach 1:
The acetyl protecting group serves multiple functions: it protects all hydroxyl groups during the coupling reaction, is easily introduced via acetic anhydride treatment, and can be removed in a single deprotection step. This universal protecting group strategy eliminates the need for different protecting groups on different hydroxyl positions, simplifying the overall process while maintaining the necessary selectivity for C-glycoside bond formation.
Solution Approach 2:
The acetyl protecting groups are intentionally designed to be temporary and removable. After the coupling reaction is complete, all acetyl groups are removed in a single deprotection step using aluminum chloride and hydrochloric acid, yielding the final product with free hydroxyl groups. This approach discards the protecting groups after they have served their purpose, avoiding the complexity of selective deprotection required when using multiple different protecting groups.
4Manufacturing precision
If expensive reagents and materials are used, then reaction yield and purity are improved, but manufacturing cost increases
Solution Approach 1:
The patent employs inexpensive, readily available reagents throughout the synthesis: aluminum chloride for Friedel-Crafts acylation, acetic anhydride for protection, and hydrochloric acid for deprotection. These common chemical reagents replace expensive specialized reagents, enabling cost-effective large-scale production while maintaining high purity through optimized reaction conditions and straightforward work-up procedures.
Solution Approach 2:
The reaction conditions are optimized to maximize yield and purity using simple reagents. The coupling reaction is conducted at controlled temperatures with specific solvent systems, and the deprotection is optimized with controlled acid treatment. These parameter optimizations ensure that even with inexpensive reagents, the product achieves high purity suitable for pharmaceutical applications, eliminating the need for expensive specialized materials.
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 process achieves high chemical and enantiomeric purity, reduces technical expenditure, and results in stable, cost-effective production of SGLT-2 inhibitors with improved yields, suitable for large-scale industrial production and long-term storage stability.
Implementation Method 1
reacting the thus obtained compound of formula VII with a reducing agent to yield empagliflozin
Implementation Method 2
in situ hydrolysis of the resulting compound of formula Vila to isolate a compound of formula VII
Data Source
AI summary
The present invention relates to novel, improved processes for the preparation of sodium glucose co-transporter 2 (SGLT-2) inhibitors and novel intermediates thereof. More particularly, the present invention relates to a novel, improved process for the preparation of gliflozin compounds such as empagliflozin and dapagliflozin, intermediates thereof. The product obtained from the processes of present invention may be amorphous or crystalline, or in the form of amorphous/crystalline solid dispersions/solutions with pharmaceutically acceptable polymers and preparation process thereof. Also, the products obtained from the present invention may be used for the preparation of medicaments for the prevention and/or treatment of diseases and conditions associated with SGLT-2 inhibition.