Synthetic method of 3,4-hydroxy benzophenone

Abstract

The invention discloses a synthetic method of 3,4-hydroxy benzophenone. The synthetic method comprises the following steps: step I, guiding bromine vapor into a glacial acetic acid solution containing pyrocatechol, carrying out column chromatography separation, taking a lower solution, and carrying out cooling crystallization; step II, mixing a solid I obtained through cooling crystallization with tetrahydrofuran and magnesium strips, guiding benzoyl chloride vapor into the obtained mixture, stirring, and heating till all the magnesium strips are dissolved, carrying out vacuum drying to obtain another solid II, and cleaning the solid II with clean water to obtain 3,4-hydroxy benzophenone. The synthetic method is simple in process, and has the advantages that pyrocatechol is used as a raw material, positioned substitution in an acetic acid solution is realized through the adoption of elemental bromine, the substituted product is mixed with metal magnesium to obtain a Grignard reagent, and the Grignard reagent reacts with benzoyl chloride, so that the reaction speed is greatly accelerated, the generation of by-products is reduced, and the production cost is reduced effectively; the production waste materials are mainly magnesium chloride and elemental bromine which can be recycled, so that the economic benefit is improved greatly, the production cost is reduced, and the market application prospect is excellent.

Description

technical field [0001] The invention belongs to the field of 3,4-dihydroxybenzophenone preparation, and in particular relates to a synthesis method of 3,4-dihydroxybenzophenone. Background technique [0002] 3,4-dihydroxybenzophenone is an important pharmaceutical intermediate and anti-ultraviolet radiation agent, and its structural formula is [0003] [0004] With the increasing demand for anti-ultraviolet and other products in domestic and foreign markets, more and more attention is paid to the synthesis and preparation of 3,4-dihydroxybenzophenone, while the traditional process for preparing 3,4-dihydroxybenzophenone is mainly Use carbon disulfide as a solvent to carry out Fried-Crafts reaction with phthalic dimethyl ether. Carbon disulfide is highly toxic and can easily cause irreversible damage to the human body. Then use pyridine hydrochloride to heat to remove the methyl group, and finally undergo extraction, etc. A series of separation steps to obtain the target...

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Problems solved by technology

[0004] With the increasing demand for anti-ultraviolet and other products in domestic and foreign markets, more and more attention is paid to the synthesis and preparation of 3,4-dihydroxybenzophenone, while the traditional process for preparing 3,4-dihydroxybenzophenone is mainly Use carbon disulfide as a solvent to carry out Fried-Crafts reaction with phthalic dimethyl ether. Carbon disulfide is highly toxic and can easily cause irreversible damage to the human body. Then use pyridine hydrochloride to heat to remove the methyl group, and finally undergo extraction, etc. A series of separation steps to obtain the target product 3,4-dihydroxybenzophenone, but the separation is difficult, and the waste after separation must undergo a series of treatments before it can be recovered. This method mainly has time-consuming and energy-consuming Disadvantages such as high cost and high cost, it is difficult to promote and apply in the market

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