Title:
PRODUCTION OF 5-PHENYLHYDANTOIN
Document Type and Number:
Japanese Patent JP3130650
Kind Code:
B2
Abstract:
PURPOSE: To provide a method for readily obtaining 5-phenylhydantoin at a low cost.
CONSTITUTION: The objective method for producing 5-phenylhydantoin is characterized by reacting urea with glyoxylic acid or methyl 2-hydroxy-2- methoxyacetate (methyl glyoxylate methyl hemiacetal) in the presence of an acid in a solvent containing benzene. Although the glyoxylic acid or methyl 2-hydroxy-2-methoxyacetate and urea react in sulfuric acid while being decomposed, the urea is more rapidly decomposed. Thereby, the urea is preferably used in a slight excess. As a result, the molar ratio of both used is preferably (1:4) to (1:1). This reaction is effectively accelerated by the presence of the acid. In this case, the acidity and dehydrating action of the acid are effective in the reaction. Sulfuric acid, phosphoric acid, etc., are specifically cited as the acid. Above all, the sulfuric acid is preferably used. The concentration of the acid is selected from the range of 1-30% and preferably used within the range of 5-15%.
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Inventors:
Masahiko Yamada
Satomi Takahashi
Satomi Takahashi
Application Number:
JP14957592A
Publication Date:
January 31, 2001
Filing Date:
June 09, 1992
Export Citation:
Assignee:
Kanegafuchi Chemical Industry Co., Ltd.
International Classes:
C07D233/74; (IPC1-7): C07D233/74
Domestic Patent References:
| JP4117363A | ||||
| JP2169578A | ||||
| JP60222465A |
Attorney, Agent or Firm:
Sota Asahina (1 person outside)