Important applications of 4'-methylacetophenone

Introduction

4'-Methylacetophenone is a colorless or nearly colorless oily liquid that solidifies at a slightly lower temperature. Has a strong hawthorn-like aroma. Slightly soluble in propylene glycol and mineral oil, insoluble in glycerol and water. Natural products exist in rosewood essential oil, mimosa flower oil, etc. It is mainly used to prepare flavors such as almonds, nuts, cherries, vanilla and strawberries[1].

Picture 1 4'-Methylacetophenone liquid

Properties of 4'-methylacetophenone

 p-Methoxyacetophenone is an aromatic compound with sweet, fruity, nutty and vanilla-like aromas. Also, p-methoxyacetophenone can sometimes smell like butter or caramel. At room temperature, p-methoxyacetophenone is solid with white and light yellow crystals. When melted, the white crystals turn into a clear liquid. The compound is used as a cigarette additive, as a flavoring agent and in food flavoring. p-Methoxyacetophenone can be found in natural castoreum (the glandular secretion of beaver). 4'-Methylacetophenone has a strong hawthorn-like aroma. The melting point is 28°C. The boiling point is 225°C (98.1kPa), 112.5°C (1.47kPa), the relative density is 1.0051 (20/4°C), the refractive index is 1.5335, and the flash point is 92. Soluble in ethanol (1ml in 10mL of 50% ethanol) and most non-volatile oils, slightly soluble in propylene glycol and mineral oil, insoluble in glycerol and water. Natural products exist in rosewood essential oil, mimosa flower oil, etc. p-Methoxyacetophenone can be synthesized from anisole and acetyl chloride through Friedel-Crafts reaction.

Uses of 4'-methylacetophenone

4'-Methylacetophenone has an aroma similar to the flower of Shanchazi, and has aromas like alfalfa, honey, strawberry, and the aroma of flowers and fruits is sharp and sweet. my country's GB2760-86 stipulates that it is allowed to use edible spices. It is mainly used to prepare flavors such as almonds, nuts, cherries, vanilla and strawberries.

The content analysis was determined according to the method one (hydroxylamine method) in the determination method of aldehydes and ketones (OT-7). The sample weight is 1g. The equivalence factor (e) in the calculation is taken as 67.09. Or according to gas chromatography (GT-10-4) with a non-polar column method. Toxicity ADI1mg/kg (CE). LD50140 Chemicalbook 0 mg/kg (rat, orally). Use limit FEMA (mg/kg): soft drinks 1.1; cold drinks 1.6; confectionery 5.2; baked goods 4.9; gummies 870; condiments 5.8; Moderation is limited (FDA § 172.515, 2000).

4'-Methylacetophenone is soluble in ethanol and most nonvolatile oils, slightly soluble in propylene glycol and mineral oil, and insoluble in glycerol and water. Natural products exist in rosewood essential oil, mimosa flower oil, etc. Uses GB27601996 stipulates that it is allowed to use edible spices. Mainly used to prepare almond, nut, cherry, fragrant and strawberry flavors. Uses Used as spices, herbicide intermediates and used in organic synthesis. It can be used in mimosa, hawthorn, acacia, locust, primrose, sunflower, hyacinth, lilac, lily, woodsy, moss and other types. It can be used together with coumarin, anisaldehyde, and jasmonaldehyde in soaps such as lavender, fragrant myrtle, saffron orchid, and new mowing grass. It can be used in a small amount in almond, vanilla and bean-flavored food flavors, and a small amount in tobacco flavor. Uses The product has a similar aroma to the flower of chamomile, and has aromas like alfalfa, honey, strawberry, and the aroma of flowers and fruits is sharp and sweet. It can be used to prepare lilac-type essence for acacia soap, etc., and can also be used as fruit food essence.

The production method of 4'-methylacetophenone

4'-Methylacetophenone is obtained by acetylation of toluene and acetic anhydride in the presence of anhydrous aluminum trichloride. Add dry toluene and powdered anhydrous aluminum trichloride into the reaction pot, add acetic anhydride dropwise with stirring, the temperature gradually rises to 90°C, and a large amount of hydrogen chloride gas is released in the reaction. The reaction was carried out until hydrogen chloride gas was no longer generated, cooled to room temperature, poured into a mixture of crushed ice and concentrated hydrochloric acid, and stirred until all the aluminum salts were dissolved. The toluene layer was separated, washed with water, washed with 10% sodium hydroxide solution until alkaline, and then washed with water. After drying over anhydrous magnesium sulfate, vacuum distillation, collecting 93-94 ℃ (0.93kPa) fractions, to obtain p-methylacetophenone, the yield is 86%. The improved method is to combine equimolar aluminum trichloride and acetyl chloride (or acetic anhydride) under heating, and then dropwise add toluene dissolved in disulfide carbon into it. The weight yield was 110% based on acetyl chloride. The production method can be obtained by free essential oil: firstly, semicarbazone is prepared, then decomposed with 10% oxalic acid aqueous solution, and then pure product is obtained by steam distillation. By the reaction of acetyl chloride, toluene and aluminum trichloride.

Reference

1 Jaimol T, Pandey A K, Singh A P. Selective acetylation of toluene to 4-methylacetophenone over zeolite catalysts[J]. Journal of Molecular Catalysis A: Chemical, 2001, 170(1-2): 117-126.

You may like