Method for preparing ambrotone

Abstract

The invention relates to a method for preparing ambrotone. The method includes steps of 1, synthesizing 3-methyl-3-pentene-2-ketone; 2, carrying out diene addition for preparing ambrotone intermediates; 3, carrying out cyclization reaction to prepare the ambrotone. Diene addition for preparing the ambrotone intermediates is carried out without catalysts by the aid of high-temperature gas-phase reaction. The method has the advantages that the ambrotone is prepared from raw materials beta-pinene, butanone and acetaldehyde, other organic solvents are omitted, high-pollution and high-carcinogenesis substances such as benzene and toluene are omitted, accordingly, the cost can be lowered, the quality of products can be effectively improved, the application range of the products can be effectively expanded, and Diels-Alder condensation reaction is carried out by the aid of the high-temperature gas-phase reaction; the Diels-Alder condensation reaction is carried out by the aid of the high-temperature gas-phase reaction or atomized small-molecule water drop and gas phases, catalysts such as Lewis acid or proton acid are omitted at reaction steps, accordingly, the production cost can be lowered, technological equipment can be simplified, post-reaction treatment working procedures can be shortened, and the purpose of zero sewage discharge can be truly achieved.

Description

technical field [0001] The invention belongs to the technical field of synthetic perfumes, in particular to a method for preparing ambroxol by only using β-pinene, methyl ethyl ketone and acetaldehyde. Background technique [0002] Ambroxone, colorless or light yellow liquid, has a woody, amber-like aroma. Its molecular formula is C 16 h 26 O, is a mixture of 2,3,8,8-tetramethyl-2-acetyloctahydronaphthalene. Due to the similar smell and effect of ambergris, it is widely used in various fields. At present, ambroxol is mainly used in: deodorant, refreshing fragrance, perfume essence blending agent and tobacco industry, etc. [0003] At present, spice companies in many countries are conducting research on the synthesis of ambroxone. In 1975, the American International Fragrance Company applied for a patent for the three-step synthesis of ambroxone. Its chemical reaction formula (1) is as follows, and must add catalyzer when this method prepares ambroxone, does not add cat...

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Problems solved by technology

[0006] Above method shortcoming is: 1, use benzene, toluene as reaction solvent, these poisonous and harmful substances are difficult to separate completely from product, have limited the scope of use of product; 2, the Diels-Alder condensation reaction of Lewis acid catalysis, because The catalyst is sensitive to water and highly corrosive, the reaction conditions are harsh, and the requirements for equipment are high

The post-treatment process is complicated, and the aluminum chloride hydrolyzate is prone to emulsification, which increases the difficulty of washing and separation; the waste acid after the reaction needs a large amount of alkali to neutralize, which increases the cost of sewage treatment and increases the difficulty of sewage treatment

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