Nippon Shokubai Kagaku Kogyo Co., Ltd.

Tsunemasa Ueno

Yutaka Morimoto

Masao Kitano

Koichi Yamamoto

Kouichi Kojima

4-Methyl-5-[(2-aminoethyl)-thiomethyl]-imidazole can be effectively produced by causing 4-methylimidazole or a salt thereof to react with at least one member selected from the group consisting of (a) a formaldehyde adduct of cysteamine, (b) 2-aminoethanethiol sulfuric acid and formaldehyde or a formaldehyde oligomer, and (c) thiazolidine or a salt thereof, in the presence of a mineral acid, removing a portion of reaction liquid out of the reaction system while maintaining molar concentration of 4-methyl-5-[(2-aminoethyl)-thiomethyl]-imidazole in the reaction system not exceeding 70 mol % based on total mol numbers of 4-methylimidazole and 4-methyl-5-[(2-aminoethyl)-thiomethyl]-imidazole, then separating a liquid containing 4-methyl-5-[(2-aminoethyl)-thiomethyl]-imidazole from the removed portion of reaction liquid, and recycling the remainder into the reaction system.

Method for production of 4-methyl-5-(2-aminoethyl)-thiomethyl)-imidazole

In a method for the production of a dithiodialdehyde represented by the formula II: ##STR1## wherein R.sup.1 and R.sup.2 are independently alkyl group of 1 to 8 carbon atoms, by condensation of an active hydrogen-containing aldehyde represented by the formula I: ##STR2## wherein R.sup.1 and R.sup.2 have the same meanings as defined above, with sulfur monochloride, the improvement which comprises simultaneously supplying said active hydrogen-containing aldehyde and sulfur monochloride to an inactive solvent, or adding said active hydrogen-containing aldehyde to a mixture of said inactive solvent with the sulfur monochloride.

Method for production of dithiodialdehyde

A method for the producing 2-[[[5-(dialkylamino)alkyl-2-furanyl]methyl]thio]-ethane amine by the reaction of cysteamine or cysteamine hydrochloride containing free hydrogen chloride with 5-(dialkyl amino)alkyl furfuryl alcohol, which method can be obtained the product in a highly yield by carrying out said reaction at a temperature in the range of 30.degree. to 80.degree. C.

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Kawasaki, Japan

Tsunemasa Ueno