Preparation method of lilial

Abstract

The invention provides a method for preparing lilial. According to the method, the lilial is synthesized from tert-butylbenzene and alpha-methylacrolein under the catalysis of a Ti-K (Na) / F-Meso-SiO2 heterogeneous catalyst. According to the catalyst, the carrier is modified through the F element, the acidity of the B acid of the catalyst is further enhanced, meanwhile, the Ti metal is doped with K and / or Na, the catalytic activity of the Ti metal is effectively improved, and due to the fact that the catalyst has the B acid site and the L acid site, and the two acidic active centers conduct synergistic catalysis, so that the process conditions are mild, the reaction time is short, the catalyst is easy to recycle, and the problem that a large amount of waste acid and solid waste are generated after a traditional catalyst is used is solved.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method of lylial. Background technique [0002] Lilial (C 14 h 20 O) It has the fragrance of lily of the valley and lily, which is soft, fresh and long-lasting. Lilial is a purely synthetic monomer fragrance, which has not been found in nature yet. In the past, the preparation of lily of the valley floral essence required the use of a large amount of raw materials such as hydroxycitronellal, lylial, neolilial, rabbit ear aldehyde, lily of the valley pyran and the like. As the dosage of hydroxycitronellal is restricted by IFRA, lylial has been banned by the European Union because of its allergenicity, lily of the valley pyran was launched late, and the market promotion of production capacity is slow, so lilial is considered to be In addition to the main spices currently used for the deployment of lily of the valley fragrance, the current annual demand ...

AI Technical Summary

Problems solved by technology

[0005] The synthetic route of lilial at present mainly contains following several kinds: the first kind is to adopt benzaldehyde and n-propionaldehyde to carry out aldol condensation reaction, carry out hydrogenation reaction again, obtain product lilial, this method yield is high, but to The price of tert-butylbenzaldehyde is relatively high, resulting in high cost of this route

The second is to use benzaldehyde and propionaldehyde as raw materials, first condense in dilute lye to generate a-methylcinnamaldehyde, use a catalyst to hydrogenate the aldehyde into 2-methylphenylpropanol, and then use tert-butyl chloride or isobutylene Carry out an alkylation reaction, and finally add the product to a mixture composed of copper chromite and liquid wax, heat dehydrogenation and fractional distillation under reduced pressure to obtain lyral, the disadvantage of this route is that it needs to use dehydrogenation The reaction and dehydrogenation reaction process have high requirements on the airtightness of the equipment, and the gas needs to be transferred in time, so the safety risk in the scale-up production process is relatively high, which limits the industrial application of this route

The third is to use tert-butylbenzene and α-methacrolein as raw materials, and react under low temperature conditions to obtain lilial (see the following formula for details). Currently, the catalysts used are titanium tetrachloride and boron trifluoride ether The compound of complex compound, this method synthetic lylial has only one-step reaction, and the product obtained is high in purity and good in quality, but the shortcoming of this present route is that yield is low, and reacts and uses Lewis acid in a large amount as catalyst at the same time, after The treatment process produces a large amount of waste acid, and the cost of the three wastes is very high. Therefore, the third route cannot be industrialized until the new catalyst is developed.

Based on the advantages and disadvantages of the above three process routes, the third route has the advantages of short process flow, less side reactions and high product purity, and has great potential for industrialization in the future. The current main problem of this method is the development of efficient catalysts. Therefore, it is necessary to find a More efficient and easily recyclable catalysts are key

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