Title:
METHOD FOR PRODUCING 2-AMINO-5-SUBSTITUTED-1,3,4-OXADIAZOLE
Document Type and Number:
WIPO Patent Application WO/2024/134942
Kind Code:
A1
Abstract:
Provided is an invention relating to a method for producing 2-amino-5-substituted-1,3,4-oxadiazole, which comprises the following steps (A) to (E). (A) A step for preparing a chlorocyanogen solution from hydrogen cyanide and chlorine. (B) A step for adjusting the amount of the hydrochloride byproduct that is secondarily produced together with chlorocyanogen in the step (A) to 0.5 equivalent or less relative to the primarily produced chlorocyanogen. (C) A step for reacting a carboxylic acid hydrazide with the chlorocyanogen solution to produce 2-amino-5-substituted-1,3,4-oxadiazole hydrochloride. (D) A step for adding a base in an amount that is greater than or equal to an equivalent obtained by combining the amount of chlorocyanogen and the amount of the byproduced hydrochloride in the chlorocyanogen solution used in the step (C) to a solution obtained in the step (C). (E) A step for cooling a solution obtained in the step (D) and containing a hydrochloride salt of the base to separate precipitated crystals.
Inventors:
KURODA Toshihiro (INC. Research Center 25-1, Matsuhama 8-chome, Kita-ku, Niigata-sh, Niigata 26, JP)
KAMIMURA Sadao (INC. Research Center 25-1, Matsuhama 8-chome, Kita-ku, Niigata-sh, Niigata 26, JP)
KAMIMURA Sadao (INC. Research Center 25-1, Matsuhama 8-chome, Kita-ku, Niigata-sh, Niigata 26, JP)
Application Number:
PCT/JP2023/025008
Publication Date:
June 27, 2024
Filing Date:
July 05, 2023
Export Citation:
Assignee:
JAPAN FINECHEM COMPANY, INC. (3-2 Uchisaiwaicho 1-chome, Chiyoda-k, Tokyo 11, JP)
International Classes:
C07D271/10; C01C3/00
Attorney, Agent or Firm:
OHTANI PATENT OFFICE (25-2 Toranomon 3-chome, Minato-k, Tokyo 01, JP)
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