Rosuvastatin Calcium Intermediate Synthesis via Hydrolysis and Reduction
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Solution Overview
Problem
The existing methods for preparing rosuvastatin calcium are hindered by the use of toxic DDQ, expensive raw materials, high energy consumption due to low-temperature reactions, and low yield, making them unsuitable for large-scale industrial production.
Innovation Solution
A method involving the hydrolysis of an ester compound in the presence of a metallic compound, followed by reduction with a borane or hydroboron and Lewis acid system to obtain the rosuvastatin calcium intermediate, using less toxic and cost-effective reagents and conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DDQ is used in the preparation process, then the reaction can proceed, but the process becomes extremely toxic
Solution Approach 1:
The patent removes DDQ from the reaction system entirely and replaces it with a two-step process using m-CPBA followed by NaBH4 reduction. This extraction of the harmful substance while maintaining the desired chemical transformation resolves the contradiction between reaction effectiveness and toxicity.
Solution Approach 2:
The patent replaces the expensive and toxic DDQ with cheaper, less toxic reagents (m-CPBA and NaBH4) that can be easily handled and disposed of. This substitution maintains reaction effectiveness while significantly reducing harmful factors.
2Reliability
If expensive raw materials such as 4-methylmorpholine-N-oxide, TPAP, and DIBAL-H are used, then the reaction can proceed, but the production cost increases
Solution Approach 1:
The patent systematically replaces expensive raw materials with cheaper alternatives: TPAP is replaced by the m-CPBA/NaBH4 system, and DIBAL-H is replaced by LiOH followed by NaBH4 reduction. These substitutions maintain reaction effectiveness while dramatically reducing production costs.
Solution Approach 2:
The patent changes the reaction conditions from requiring expensive, sensitive reagents to using more robust, cost-effective reagents that operate under milder and more economical conditions, thereby reducing production costs while maintaining effectiveness.
3Reliability
If DIBAL-H reacts at low temperature (minus 70 to minus 40 degrees centigrade), then the reaction can proceed, but energy consumption and production costs increase
Solution Approach 1:
The patent fundamentally changes the temperature parameter from -70 to -40°C to much milder conditions (0°C to room temperature) by using LiOH for hydrolysis followed by NaBH4 reduction. This parameter change eliminates the need for expensive low-temperature equipment and significantly reduces energy consumption.
Solution Approach 2:
The patent removes DIBAL-H and its associated low-temperature requirements from the process, replacing them with reagents that operate at ambient or mildly controlled temperatures, thereby eliminating high energy consumption.
4Reliability
If the existing preparation method is used, then the reaction can proceed, but the yield is low
Solution Approach 1:
The patent divides the single-step DIBAL-H reduction into two separate steps: (1) LiOH-mediated hydrolysis to form the intermediate carboxylic acid, and (2) NaBH4 reduction to form the final product. This segmentation allows each step to be optimized independently, resulting in higher overall yield while maintaining feasibility.
Solution Approach 2:
By using LiOH and NaBH4 instead of DIBAL-H, the patent achieves better yield through a two-step process that avoids the side reactions and incomplete reductions associated with DIBAL-H, while also using more cost-effective reagents.
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 reduces production costs, eliminates the need for toxic reagents, and increases yield, making it suitable for industrial-scale production while maintaining high purity and efficiency.
Implementation Method 1
hydrolyzing an ester compound represented by formula II in the presence of a metallic compound to obtain a carboxylic acid compound represented by formula III
Implementation Method 2
reducing the carboxylic acid compound in the presence of a reductant to obtain the rosuvastatin calcium intermediate
Data Source
AI summary
A method for preparing a rosuvastatin calcium intermediate represented by formula I. The method includes: hydrolyzing an ester compound represented by formula II (in which, R represents C1-C5) in the presence of a metal compound to obtain a carboxylic acid compound represented by formula III; and reducing the carboxylic acid compound in the presence of a reductant.