1. Standard synthesis technique
The traditional synthesis method is the Claisen condensation response of benzaldehyde and also acetone under the activity of weaken base. Mix acetone and also water down sodium hydroxide solution in proportion, add human benzaldehyde dropwise within 30 minutes after cooling, manage the temperature level at 30 ° C, and continue stirring for 30 min after the addition. Readjust the pH to 6 ~ 7 with thin down hydrochloric acid, let it represent 1 h, and also divide the yellow oil. Extract the lower layer with benzene, incorporate the remove and oil, wash two times with saturated saline, separate the water layer, recover benzene, dry with calcium chloride, include dry decolorizing carbon, filter, and also distill the filtrate under reduced stress to obtain the ended up product of Benzalacetone. In general, the item yield is lower than 70%, and it relates to the type and quantity of antacids, response temperature, and also the ratio of reaction materials.
Although the process is mature, the reaction is light as well as the yield is secure, this method has the downsides of huge waste water discharge, severe pollution, loss of raw materials as well as items, low return as well as the driver can not be reused. In the separation procedure after the response, the antacid catalyst needs to be reduced the effects of, and the quantity of contaminant discharge is large, causing significant pollution to the environment. Both the raw product and water are miscible, and also it is difficult to divide the excess resources. Therefore, this approach has actually been removed in real commercial manufacturing.
2. Synthesis technique of stage transfer driver
The existing study on the synthesis of Benzalacetone mostly focuses on boosting or changing catalysts, specifically replacing stage transfer stimulants. Including a stage transfer catalyst to the response system, because it can move the reactant from one phase to an additional, makes the ionic substance and also the water-insoluble organic compound respond efficiently in a reduced polar solvent, speeds up the response, and also creates rate increase. Phase-transfer catalytic synthesis is a reliable, inexpensive as well as useful technique for this response
3. Supercritical synthesis
Mao Jianyong et al. suggested a technique for preparing benzylidene acetone under supercritical (temperature 350 ° C, stress (25 ± 1) MPa) problems, acetone as well as benzaldehyde were pumped right into a 250 ° C preheater with a high-pressure metering pump, and also the The preheated product is pumped into a pipeline activator at 400 ° C, as well as the pressure is (25 ± 1) MPa, to ensure that the catalysts get to a supercritical state, react for 20 mins, and condense in one action to form Benzalacetone. The qualities of this development, the return is as high as 92%, no need to make use of any kind of solvent, there is no problem in water separation in post-treatment, the response time is considerably reduced, it is a pipe response, and also constant reaction can be accomplished. The downside is that the temperature level is high and the pressure is high. and high security demands. As long as this course resolves the tools problem, it has excellent practical value and can be industrialized.