Chemical Properties
4-chlorobenzaldehyde appears as colourless to light yellow crystalline powder. Insoluble in water, easily soluble in ethanol, ether, benzene, soluble in water, acetone. Can be volatilized with water vapor. It can produced by the oxidation of 4-chlorobenzyl alcohol. 4-chlorobenzaldehyde is the intermediate of fungicide tebuconazole and plant growth regulator uniconazole.
Uses
4-Chlorobenzaldehyde is used as an intermediate for the manufacture of dyestuffs, optical brighteners, pharmaceuticals, agricultural chemicals and metal finishing products.
Preparation
4-Chlorobenzaldehyde can be obtained by chlorinated hydrolysis of p-chlorotoluene: add p-chlorotoluene and phosphorus trichloride to the reaction pot, raise the temperature to 155°C under light and pass chlorine. Control the temperature at 160-170℃ and pass chlorine to the calculated amount to obtain the chlorination solution. Add it to concentrated sulfuric acid with stirring, and stir for 5h at room temperature. let it stand and stratify, take the lower layer into ice water to crystallize, and filter it when it is cold to below 5℃. The filter cake was washed with ice water to obtain the crude product, distilled under reduced pressure and collected 108-111℃ (3.33kPa) fraction to obtain p-chlorobenzaldehyde.
General Description
Colorless to yellow powder or white crystalline solid. Pungent odor.
Air & Water Reactions
4-Chlorobenzaldehyde is sensitive to exposure to air. Insoluble in water.
Reactivity Profile
4-Chlorobenzaldehyde is sensitive to exposure to air. 4-Chlorobenzaldehyde is also sensitive to light. REACTIVITY: 4-Chlorobenzaldehyde is incompatible with strong bases, strong oxidizers and strong reducing agents.
Fire Hazard
4-Chlorobenzaldehyde is combustible.
Purification Methods
Crystallise it from EtOH/water (3:1), then sublime it twice at ~50o/2mm. [Beilstein 7 H 235, 7 IV 568.]
