Takasago International Corporation

Teruyoshi Akiyama

Takashi Miura

Toshimitsu Hagiwara

Akira Amano

Yoshifumi Yuasa

Akio Tachikawa

Toyohiko Kobayashi

Hiroyuki Kenmochi

A method for safely and efficiently producing high purity 3-l-menthoxypropane-1,2-diol and intermediates to be used in the method. As shown in the following reaction formula, 3-l-menthoxypropane-1,2-diol represented by the chemical formula (IV) is produced by adding l-menthol to a 1,2-epoxy-3-halogenopropane represented by the general formula (I) (wherein X represents a halogen atom) in an organic solvent in the presence of a Lewis acid, thereby producing a 1-halogeno-3-l-menthoxypropan-2-ol represented by the general formula (II), allowing the first intermediate to react with an alkali metal salt of an aliphatic carboxylic acid having from 1 to 5 carbon atoms to produce a 1-acyloxy-2-substituted-3-l-menthoxypropane represented by the general formula (III) and then hydrolyzing the second intermediate.

Method for producing 3-l-menthoxypropane-1,2-diol

A process for producing highly pure 3-1-menthoxypropane-1,2-diol safely and efficiently, and an intermediate to be used in the process. 3-1-menthoxypropane-1,2-diol represented by the chemical formula (IV) is produced by adding 1-menthol to a 1,2-epoxy-3-halogenopropane represented by the following general formula (I) (wherein X represents a halogen atom) in an organic solvent in the presence of a Lewis acid to produce a novel 1-halogeno-3-1-menthoxypropan-2-ol represented by the following general formula (II), then, epoxidating it with a base in the presence of a phase transfer catalyst to produce a 1,2-epoxy-3-1-menthoxypropane represented by the chemical formula (III), and further hydrolyzing it.

Process for producing 3-1-menthoxypropane-1,2-diol

To offer a method of producing useful para-menthane-3,8-diol having the excellent repellent action to harmful living things, including noxious insects, in high purity and high yield, simply, and economically by the use of citronellal as a raw material compound. The above-mentioned problems are resolved by the production method of this invention wherein citronellal is treated with aqueous sulfuric acid solution of 0.02 to 1.0 wt. % in concentration to produce para-menthane-3,8-diol. In case of recovering the produced para-menthane-3,8-diol, a method is preferably adopted, wherein after the reaction product is extracted with an aliphatic hydrocarbon solvent of 5 to 8 in carbon number, the extract is cooled down at temperature higher than the melting point of said aliphatic hydrocarbon solvent and of -10.degree. C. or less to crystallize para-menthane-3,8-diol.

Method for producing para-menthane-3,8-diol

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Kanagawa, Japan

Teruyoshi Akiyama