Propyl isobutyl acetophenone (PIBPA) is an important organic chemical raw material, which is widely used in the fields of pharmaceuticals, pesticides and spices. In this paper, we will introduce a manufacturing method of propyl isobutyl acetophenone, which is made from acetophenone and isobutyraldehyde as raw materials, after condensation, alkylation and other reaction steps.
I. Raw materials and equipment
1. Raw materials: acetophenone, isobutyraldehyde, propanol, sulfuric acid, sodium hydroxide and so on.
2. Equipment: reaction kettle, stirrer, condenser, water separator, thermometer, pH meter and so on.
2. Manufacturing steps
1. Condensation reaction
Acetophenone and isobutyraldehyde are added into the reaction kettle at the ratio of molar ratio of 1:1.2, a small amount of sulfuric acid is added as a catalyst, and the reaction is stirred and heated up to 80-90 ℃, and the reaction is carried out for 6-8 hours. During the reaction, the pH value was checked regularly and adjusted with sodium hydroxide solution to keep the pH value between 6-7. At the end of the reaction, cool to room temperature and precipitate the solid product.
2. Alkylation reaction
The solid product obtained from the condensation reaction and propanol were added into the reaction kettle at a molar ratio of 1:1.5, a small amount of sulfuric acid was added as a catalyst, and the reaction was stirred and heated up to 120-130°C for 8-10 hours. The pH value needs to be checked regularly during the reaction and adjusted with sodium hydroxide solution to keep the pH value between 6-7. At the end of the reaction, it was cooled to room temperature to obtain the crude product of propyl isobutyl acetophenone.
3. Refining
Add the crude product of propyl isobutyl acetophenone into the distillation kettle, heat and distill, collect the fraction at 150-170°C, which is pure propyl isobutyl acetophenone.
III. Precautions
1. In the condensation and alkylation reaction, it is necessary to control the pH value between 6-7 to ensure the smooth progress of the reaction.
2. During the reaction, the temperature and pH of the reaction solution need to be detected regularly to adjust the reaction conditions in time.
3. During the distillation process, the distillation temperature and pressure need to be controlled to ensure the purity and yield of the product.
4. Safety and environmental protection
1. In the production process, it is necessary to strictly follow the safety operation regulations to ensure the safety of employees and equipment.
2. For the waste and by-products, they need to be reasonably treated and utilized to avoid pollution to the environment.
In conclusion, the manufacturing method of propyl isobutyl acetophenone introduced in this paper has the advantages of easy availability of raw materials, simple operation, high yield, etc., and is suitable for industrialized production. At the same time, attention needs to be paid to safety and environmental protection in the production process to ensure the quality of the product and the sustainable development of the environment.
