Manufacturing method of ethyl propylcyanoacetate
I. Introduction
Ethyl propylcyanoacetate is an important chemical raw material, which is widely used in the fields of medicine, pesticide and plastics. In this paper, the manufacturing method of ethyl propylcyanoacetate will be introduced in detail, including raw material preparation, reaction steps, post-treatment and precautions.
II. Raw material preparation
1. Propyl cyanide: propyl cyanide is the main raw material for the preparation of ethyl propylcyanoacetate, which is generally produced through the addition reaction of acrylonitrile and hydrogen.
2. Ethyl chloroacetate: Ethyl chloroacetate as another raw material can be prepared by esterification reaction between chloroacetic acid and ethanol.
III. REACTION STEPS
1. In a reactor equipped with a stirrer, thermometer and reflux condenser, add a quantitative amount of propyl cyanide and ethyl chloroacetate.
2. Turn on the stirrer, heat the reactor to a certain temperature, and keep the constant temperature reaction for a certain time.
3. Monitor the progress of the reaction by Thin Layer Chromatography (TLC) and stop heating when the reaction of the raw materials is complete.
4. Cool the reactor to room temperature, transfer the reaction solution to a separatory funnel, wash with water several times and discard the aqueous phase.
5. The organic phase was dried with anhydrous sodium sulfate, filtered to remove the desiccant, to obtain ethyl propylcyanoacetate crude product.
4. Post-treatment
1. Transfer the crude ethyl propylcyanoacetate to a distillation kettle and carry out atmospheric pressure distillation to collect the target fraction.
2. The ethyl propylcyanoacetate bouillon obtained by distillation was kept in a sealed brown reagent bottle, avoiding light and high temperature.
V. Precautions
1. Both propyl cyanide and ethyl chloroacetate are toxic chemicals, so you need to strictly follow the laboratory safety regulations and wear protective gears during the operation.
2. Keep constant temperature during the reaction to avoid too high or too low temperature affecting the reaction speed and selectivity.
3. When washing the organic phase with water, the water temperature should be controlled to avoid hydrolysis of ethyl propyl cyanoacetate.
4. Ensure that the anhydrous sodium sulfate is completely dry during the drying process to avoid moisture being carried over to the subsequent distillation step.
5. The heating rate should be controlled during distillation to avoid localized overheating leading to product decomposition.
6. Conclusion
Through the above steps, we can successfully prepare ethyl propylcyanoacetate. During the actual operation, laboratory safety norms should be strictly observed and the operation steps should be adjusted according to the specific experimental conditions to ensure the purity and yield of the product. The manufacturing method described in this paper is a basic reference, the specific experimental operation should be carried out under the guidance of professionals.
