Preparation method of butyl p-hydroxybenzoate

Abstract

The invention discloses a preparation method of butyl p-hydroxybenzoate, comprising the following steps of: firstly cleaning a 4A zeolite by distilled water, and controlling activation temperature; activating for a period of time, cooling, and then weighing a certain amount of the 4A zeolite; soaking in a toluenesulfonic acid solution; removing a water solution, and then drying to obtain a needed catalyst; adding p-hydroxybenzoic acid, butanol, toluene, benzyltriethylammonium chloride and the catalyst to a flask together, reacting in a reflux state, and also separating water; after the reaction is finished, filtering to remove the catalyst, and steaming unreacted and toluene; adding residues to cold water for intensely stirring so as to separate out white crystals; then neutralizing unreacted acid by a sodium carbonate solution till the sodium carbonate solution becomes alkalescent; filtering, and drying to obtain a product of the butyl p-hydroxybenzoate. The invention has low cost, easy storage, no side reaction in the production process, and corrosive damage on equipment.

Description

technical field [0001] The invention relates to a preparation method of butyl p-hydroxybenzoate. Background technique [0002] The trade name of butyl paraben is butylparaben, which is one of the safe and effective preservatives used in the world, and can be widely used in the manufacture of food, cosmetics, daily chemicals and pharmaceuticals. At present, its synthesis method usually adopts p-hydroxybenzoic acid and n-butanol, and directly prepares it under the action of concentrated sulfuric acid, but this method has problems such as serious equipment corrosion and prone to dehydration side reactions. In recent years, it has been reported to use heteropolyacids, super solid acids, etc. as catalysts. Although the effect is good, the price is relatively expensive, and there is a certain gap with the actual application. There is also the use of ferric chloride as a catalyst. The disadvantage is that it is easy to absorb moisture, is difficult to preserve, and is soluble in t...

AI Technical Summary

Problems solved by technology

At present, its synthesis method usually uses p-hydroxybenzoic acid and n-butanol, and is directly prepared under the action of concentrated sulfuric acid, but this method has problems such as serious equipment corrosion and easy dehydration side reactions.

In recent years, it has been reported to use heteropolyacids, super solid acids, etc. as catalysts. Although the effect is good, the price is relatively expensive, and there is a certain gap with the actual application.

There is also the use of ferric chloride as a catalyst. The disadvantage is that it is easy to absorb moisture, is difficult to preserve, and is soluble in the organic reaction system, resulting in a dark product after the reaction. It needs to be decolorized with activated carbon to remove it, and the operation is very troublesome.