Nippon Kokan Kabushiki Kaisha

Itaru Sakai

Takao Ikariya

Masanori Itagaki

Masatsugu Mizuguchi

Osamu Tajima

According to a method of manufacturing a diphenylmethane dicarbamic acid ester by reacting an N-phenyl carbamic acid diester with a methylating agent in an aqueous acid solution, the aqueous acid solution is an aqueous inorganic acid solution, and the concentration of the N-phenyl carbamic acid ester in the aqueous acid solution is not more than the solubility thereof at the reaction temperature.

Method of manufacturing diphenylmethane dicarbamic acid diesters

The present invention relates to a method of manufacturing aromatic urethane, an aromatic mononitro-compound, an aromatic primary amine, and carbon monoxide being reacted using a catalyst containing a platinum group metal-containing compound as a major constituent to prepare N,N'-di-substituted urea. The resultant N,N'-di-substituted urea is reacted with a hydroxyl group-containing organic compound to prepare an aromatic primary amine and aromatic urethane, and the aromatic primary amine is separated to obtain aromatic urethane.

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Yokohama, Japan

Itaru Sakai