Preparation method of 3-methyl-5-phenyl-amyl alcohol

Abstract

The invention provides a preparation method of 3-methyl-5-phenyl-amyl alcohol. The preparation method comprises the following steps of phenyl-dihydropyran preparation, wherein the weight ratio of solid acid to 3-methyl-3-butenol is 1:(100-5,000), the weight ratio of xylene to 3-methyl-3-butenol is (0.5-2.0):1.0, and the weight ratio of benzaldehyde to 3-methyl-3-butenol is (1.2-3.0):1.0; a hydrogenation reaction, wherein the hydrogenation reaction is conducted for 1 h to 15 h at the temperature of 45 DEG C to 150 DEG C under the pressure of 0.3 MPa to 2.5 MPa. According to the preparation method, phenyl-dihydropyran is efficiently generated by mainly adopting a vacuum tower type reactor and a negative-pressure cyclization technology; a cocatalyst is added in the hydrogenation reaction, and therefore it is guaranteed that the conversion rate and the selectivity are high, the catalyst is recycled for multiple batches and is low in cost, the yield of the final product is high, and industrialized production can be achieved.

Description

technical field [0001] The invention belongs to the field of fine chemical industry, relates to the preparation method of compound 3-methyl-5-phenyl-pentanol, and provides the application of the novel method in the synthesis of perfume 3-methyl-5-phenyl-pentanol. Background technique [0002] Phenopentanol, the chemical name is 3-methyl-5-phenyl-pentanol, also known as phenylisohexanol, and its structural formula is: , is a commonly used rose fragrance series of spices. Due to its extraordinary fragrance persistence and natural rose absolute floral fragrance, it is widely used in high-end daily fragrance, personal care and home care products. At present, the annual output of 3-methyl-5-phenyl-pentanol in the world is increasing year by year, and the market usage is also increasing year by year. [0003] At present, the preparation method of synthesizing 3-methyl-5-phenyl-pentanol is mainly the preparation process route of benzaldehyde and isopentenol: [0004] Swiss pate...

AI Technical Summary

Problems solved by technology

[0009] (1) Waste acid water is produced during the production process, causing environmental pollution;

[0010] (2) The cyclization reaction uses normal pressure azeotropic method to remove water, and a solvent that is azeotropic with water must be added, and when azeotropic with water, the content of water in the azeotropic composition is relatively large, and solvents such as toluene and xylene are generally selected. The addition of a high boiling point solvent results in a high reaction temperature during the preparation of the intermediate phenyl-dihydropyran;

[0011] (3) In the process of preparing the intermediate phenyl-dihydropyran, the reaction yield is low, the highest is only 80%; the purity of phenyl-dihydropyran is low;

[0012] (4) Hydrogenation reaction, the reaction conversion rate is low. In the patent of Jiangsu Luyuan Fine Chemical Co., Ltd., the patent number is CN201510158694.6. In the example, it is mentioned that the conversion rate of palladium carbon hydrogenation is 93%, and the reaction selectivity is low. low yield;

[0014] The cost of catalyst use is high. Due to the low toxicity and high price of the palladium catalyst, the cost of 3-methyl-5-phenyl-pentanol cannot be reduced to a certain height for a long time, so that 3- The use of methyl-5-phenyl-pentanol is extremely limited and it is difficult to produce industrially

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