Rosuvastatin Calcium Synthesis via Segmented Intermediates
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Solution Overview
Problem
Current methods for synthesizing rosuvastatin calcium are inefficient due to long reaction times, low yields, use of toxic materials, multiple steps of high vacuum distillation, and poor product purity, making industrialization difficult.
Innovation Solution
A new synthetic method using 4-4′-fluorophenyl-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyrimidine-5-formaldehyde as the starting material, involving condensation with a nitrilized reagent to produce intermediates that are then reduced and condensed to form rosuvastatin calcium, eliminating the need for toxic reagents and high vacuum distillation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional synthetic methods are used, then rosuvastatin calcium can be produced, but the synthesis route is long and the yield is low
Solution Approach 1:
The synthesis route is divided into distinct modular steps: condensation of pyrimidine formaldehyde with nitrile to form intermediate I, reduction to intermediate II, and condensation with side chain D to form the final product. This segmentation allows optimization of each step independently, reducing overall synthesis time and improving yield.
Solution Approach 2:
The patent prepares and characterizes intermediates I and II in advance with defined structures and purification methods. By establishing reliable intermediate preparation steps first, the overall synthesis process becomes more efficient and reproducible, reducing total reaction time.
2Manufacturing precision
If traditional purification methods are used, then product purity can be achieved, but multiple steps of high vacuum distillation and silica gel column purification are required
Solution Approach 1:
The patent extracts and removes toxic reagents (PBr3, KCN, NaCN) and complex purification steps (high vacuum distillation, silica gel column) from the synthesis process. Alternative reagents and simplified purification methods are introduced, maintaining product purity while reducing device complexity and safety hazards.
Solution Approach 2:
The patent changes the physical and chemical parameters of the synthesis process, including using milder reaction conditions, alternative solvents, and modified purification parameters. These changes enable achieving high product purity without requiring complex high vacuum distillation and multiple silica gel column purifications.
3Productivity
If traditional reagents are used, then the synthesis can proceed, but highly toxic and severely pollutive materials are required
Solution Approach 1:
The patent converts harmful toxic reagents into beneficial or harmless alternatives. PBr3 is replaced with less toxic phosphorus reagents, and cyanide reagents (KCN, NaCN) are replaced with non-toxic nitrile and amine reagents. This maintains synthesis capability while eliminating toxicity and pollution.
Solution Approach 2:
The patent uses readily available, non-toxic reagents that can be easily disposed of after use, replacing expensive and hazardous toxic reagents. The new reagent system maintains synthesis effectiveness while being environmentally friendly and safer for industrial production.
4Quantity of substance
If traditional synthetic routes are used, then intermediates can be obtained, but most intermediates are viscous and difficult to purify
Solution Approach 1:
The patent modifies the chemical structure and physical properties of intermediates through parameter changes in the synthesis process. Intermediate I and II are designed to have favorable solubility and crystallization properties, transforming them from viscous difficult-to-purify substances into easily handleable compounds with defined melting points and solubility characteristics.
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 shortens the synthesis route, increases yield, and improves product purity, making it easier to industrialize and reducing production costs while avoiding toxic materials and complex purification steps.
Implementation Method 1
condensation of the substitution pyrimidine-5-formaldehyde with the nitrilized reagent
Implementation Method 2
Reduce the acrylonitrile group to the acrolein group
Implementation Method 3
condensed to form rosuvastatin calcium
Data Source
AI summary
The present invention publicly discloses a synthetic method and intermediates of rosuvastatin calcium and synthetic methods of the intermediates. The synthetic method uses 4-4′-fluorophenyl-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyridine-5-formaldehyde as the raw material, includes 4-4′-fluorophenyl-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyridine-5-acrylonitrile (intermediate I) from a nitrilized reaction, and 4-4′-fluorophenyl-6-isopropyl-2-(N-methyl-N-methylsulfonylamino)pyridine-5-acraldehyde (intermediate II) from an aldehydized reaction of the intermediate I, and further goes through such unit processes as side-chain extension, ketone-group reduction, ethyl-group hydrolysis and neutralization reaction or decomposition reaction to obtain rosuvastatin calcium. The nitrilized reagent can be phosphate diethylacetonitrile, acetonitrile, etc.; the aldehyde reductant can be diisobutyl aluminum hydride, red aluminum, etc.; and the ketone-group reductant can be diethylmethoxyborane, NaBH4, KBH4, etc.