Kureha Kagaku Kogyo K.k.

Japan Hydrazine Co., Ltd.

Fumio Toda

Shunji Hyoda

Youichi Hasegawa

A method of producing a choline having a high purity without containing by-products by using a molecule-inclusion complex of the choline as a starting material. A choline inclusion complex without containing by-products is obtained by reacting an aqueous solution of the choline containing, as by-products, those cholines to which are added ethylene oxides with host molecules such as of 1,1'-bis-.beta.-naphthol, and is further reacted with a carbon dioxide gas in order to obtain an aqueous solution of a choline carbonate and/or a choline bicarbonate of a high purity, which is then subjected to the electrolysis using a cation-exchange membrane as a diaphragm, in order to obtain an aqueous solution of the choline of a high purity without containing by-products. The choline that is obtained is a strongly basic compound having a high purity and is very useful as a photoresist-developing solution.

Method of producing choline of a high purity

A process for the separation of an alkyl-substituted naphthalene from a mixture containing the desired alkyl-substituted naphthalene and at least one isomer thereof comprises placing 9,9'-bianthracene in contact with the mixture to form a clathrate complex of the formula ##STR1## wherein A represents 2-methylnaphthalene, 2-isopropyl-naphthalene of 2,6-diisopropylnaphthalene, collecting the clathrate complex by filtration, subjecting the clathrate complex to thermal decomposition, and then recovering the alkyl-substituted naphthalene derivative.

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Shigenobu, Japan

Fumio Toda