2-Nitratoethyl Acrylate Synthesis via Single-Step Nitration
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Solution Overview
Problem
Conventional processes for synthesizing 2-nitratoethyl acrylate result in low yields and incidental formation of Ethylene Glycol Dinitrate (EGDN) and hydrogen chloride, with complex steps and expensive starting materials.
Innovation Solution
A new process utilizing 2-hydroxyethyl acrylate with a single reactive step, employing a mixture of nitric acid and sulfuric acid, which minimizes EGDN formation and eliminates hydrogen chloride production, allowing for high-yield separation and reuse of the acid phase, and using commercially available and inexpensive starting materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional two-step processes are used to synthesize 2-nitratoethyl acrylate, then the process can be implemented with known starting materials, but the overall yield is low (21-42%) and EGDN is accidentally formed
Solution Approach 1:
The conventional two-step process is replaced with a single-step direct nitration process. Instead of first synthesizing β-nitratoethanol and then reacting it with acrylyl chloride, the invention directly nitrates 2-hydroxyethyl acrylate in one step to produce 2-nitratoethyl acrylate, eliminating the intermediate step and the associated byproduct formation
Solution Approach 2:
The harmful EGDN formation pathway is eliminated by selecting a starting material (2-hydroxyethyl acrylate) that contains only one hydroxyl group capable of nitration. This structural choice extracts or removes the possibility of forming di-nitratoethanol (EGDN) from the reaction pathway
2Ease of manufacture
If conventional processes are used, then synthesis can proceed with established methods, but hydrogen chloride is formed as a byproduct
Solution Approach 1:
The harmful hydrogen chloride byproduct is eliminated by changing the reaction pathway. Instead of using acrylyl chloride which releases HCl during nitration, the invention uses 2-hydroxyethyl acrylate with a nitration mixture that does not generate hydrogen chloride, thereby extracting the harmful byproduct formation from the process
Solution Approach 2:
The reaction parameters are changed by selecting different starting materials and reaction conditions. The invention uses a nitration mixture of nitric acid and sulfuric acid with 2-hydroxyethyl acrylate at controlled temperatures (0-5°C), which changes the chemical parameters to eliminate HCl formation while maintaining ease of manufacture
3Adaptability or versatility
If multi-step processes are used, then complex synthesis pathways can be explored, but the number of steps increases and cost increases
Solution Approach 1:
The two-step conventional process is merged into a single-step direct nitration process. The invention combines the nitration reaction and the ester formation into one simultaneous reaction step, where 2-hydroxyethyl acrylate is directly nitrated to form 2-nitratoethyl acrylate, thereby reducing the number of steps and associated complexity
Solution Approach 2:
The synthesis pathway is segmented to use a commercially available starting material (2-hydroxyethyl acrylate) that can be directly nitrated, eliminating the need to synthesize intermediate compounds. This segmentation simplifies the overall process while maintaining versatility in obtaining the final product
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 a significantly higher yield of 85% purity 2-nitratoethyl acrylate, reducing EGDN and hydrogen chloride formation, and enabling efficient reuse of the acid phase, with potential medicinal applications.
Implementation Method 1
2-hydroxyethyl acrylate is added to a stirred, cooled mixture that has a molar excess of concentrated nitric acid combined with a comparable volume of concentrated sulfuric acid
Implementation Method 2
2-nitratoethyl acrylate may be separated from the nitrating acid mixture of nitric acid and sulfuric acid by simple phase separation
Data Source
AI summary
An elegant process for the synthesis of 2-nitratoethyl acrylate is a single reactive step. A 2-hydroxyethyl acrylate having only one hydroxyl group is nitrated in a 1:1 volumetric mixture of nitric acid and sulfuric acid therein forming 2-nitratoethyl acrylate. The 2-nitratoethyl acrylate is minimally soluble in a quenched cold acid water mixture, which enables relatively easy isolation of about 96% purity 2-nitratoethyl acrylate at a yield of about 85%.