Nov. 15, 2021
Benzaldehyde (C6h5cho) is an organic compound that is formed when the hydrogen of benzene is replaced by an aldehyde group. Benzaldehyde is the simplest and most commonly used aromatic aldehyde in the industry. At room temperature, it is a colourless liquid with a peculiar almond odour. Benzaldehyde (CAS: 100-52-7) is the main component of bitter almond oil extract. It can also be extracted from apricots, cherries, bay leaves and peach kernels. This compound is also found in nuts and kernels in the form of a combination with glycosides (Amygdalin, Amygdalin). Nowadays, benzaldehyde is mainly prepared from toluene by different means.
Benzaldehyde can be prepared in a number of ways. Currently, the main methods of preparation are liquid chlorination or toluene oxidation. Methods that have been phased out include incomplete oxidation of benzyl alcohol, alkaline hydrolysis of benzoyl chloride, and the addition of benzene with carbon monoxide.
Benzaldehyde CAS: 100-52-7
Benzaldehyde can be oxidised to a white, unpleasant-smelling benzoic acid solid that crystallises on the inner walls of the container. Benzyl alcohol can be prepared by hydrogenating benzaldehyde or by the oxidative reduction of benzaldehyde itself in an alcoholic solution of potassium hydroxide (the products are potassium benzoate and benzyl alcohol). Cinnamic acid is produced by the reaction of benzaldehyde with anhydrous sodium acetate and acetic anhydride. Alcoholic solutions of potassium cyanide can be used to catalyse the condensation of benzaldehyde to produce benzoin.
Disproportionation of benzaldehyde in concentrated alkali solutions (Cannizzaro reaction, Cannizarro reaction): one aldehyde is reduced to the corresponding alcohol, while the other aldehyde is oxidised to a carboxylate. The rate of the reaction depends on the substituents on the aromatic ring.
Although widely used as a commercial food flavouring agent and industrial solvent, benzaldehyde is mainly used in the synthesis of a variety of other compounds, from pharmaceuticals to plastic additives. Benzaldehyde is also an important intermediate in the production of perfumes, fragrances and some aniline dyes.
1. Benzaldehyde is an important chemical raw material used in the manufacture of lauric aldehyde, lauric acid, phenylacetaldehyde and benzyl benzoate, also used in perfumes.
2. Benzaldehyde can be used as a special fragrance head in trace amounts for floral formulations such as lilac, white orchid, jasmine, violet, acacia, sunflower, sweet pea, plum, orange blossom, etc.
3. Also used in soaps and as an edible flavouring for almonds, berries, cream, cherries, coconuts, apricots, peaches, pecans, plums, vanilla beans, spices and other fragrances. Alcoholic flavours such as rum, brandy and other types are also used.
4. Benzaldehyde is an intermediate for the herbicide wild swallow blight and the plant growth regulator diamine.
5. The use of food flavourings is temporarily permitted under GB 2760-1996. It is mainly used in the preparation of almonds, cherries, peaches, nuts and other types of flavourings in amounts of up to 40%. As a flavouring agent for canned sweet cherries, add 3 ML of sugar water per kg.
6. Intermediates pharmaceuticals, dyestuffs and perfumes. Used in the production of M-oxobenzaldehyde, lauric acid, lauric aldehyde, pint green, benzyl benzoate, benzylidene aniline, benzylidene acetone, etc. Used in the mixing of flavours for soaps, food flavourings, etc.