A-bromocinnamaldehyde physicochemical properties and preparation method

a-Bromocinnamaldehyde

[Alias] 2-bromo-3-phenyl acrolein

[Structural formula]

[Physical and chemical properties] Colorless needle-like crystals, the pure product has a melting point of 72-73°C, and the industrial product has a melting point of 69-72°C

[Preparation method] There are many routes for the synthesis of a-bromocinnamaldehyde (abbreviated as a-BCA), but the method that is relatively simple, economical and suitable for industrial basic production is to start with cinnamaldehyde, add with bromine, and then eliminate Hydrogen bromide

(1) Synthesis principle

The principle of synthesizing a-BCA with cinnamaldehyde and bromine as the main raw materials and using glacial acetic acid as the solvent has two main aspects: on the one hand, there is a large π-π conjugation effect, and the total energy is lower than the isolated π bond, so it is better than the isolated double The bond system is stable and the unsaturation is reduced; on the other hand, the carbonyl group is an electron withdrawing group.

In order to increase the conversion rate, an appropriate amount of base and alcohol must be added when the reaction is appropriate to promote the reaction and shorten the reaction time

Figure 7-16 a-BCA synthesis process flow

(2) Improvement method 1

Lu Yujing uses anhydrous sodium carbonate as alkali reagent in patent CN1086204 to control the reaction temperature below 80°C

(3) Improvement method 2

The product of the traditional method has darker color and difficult recrystallization.

In a 150mL four-neck flask equipped with electric stirring, thermometer, dropping funnel and reflux condenser, add 11.

[Application] a-Bromocinnamaldehyde is a broad-spectrum bactericide and deodorant.

(1) Sterilization mechanism

Cinnamaldehyde itself has a certain bactericidal effect, and its antibacterial property is related to the bilayer permeability of the phospholipid protein of the bacterial cell membrane.

(2) Sterilization

The preparation of this product can be used as a disinfectant for hospitals, public places, toilets, disinfectants for medical equipment in hospitals, disinfectants for household items, insect repellents for animals, and preservatives for biological corpses

Table 7-23 is the minimum inhibitory concentration of a-BCA

(3) Anti-mold and deodorizing

Incorporating natural or synthetic fibers, it can play a long-term anti-mildew and anti-moth effect

Table 7-23 Minimum inhibitory concentration of a-BCA