Document Type and Number:
Japanese Patent JPS647071
Kind Code:
B2
Abstract:
PURPOSE:To obtain a binuclear diphenylmethane dicarbamate in high yield, by carrying out the condensation reaction of an N-phenylcarbamate with a methylenation agent in two steps, and separating and recycling the unreacted materials in each step. CONSTITUTION:An N-phenylcarbamate of formula (R is alkyl, etc.; R' is H, alkyl, etc.; r is 0-4) is made to react with a methylenation agent (e.g. formaldehyde) to obtain diphenylmethane dicarbamate. In the above process, the compound of formula is made to react in excess liquid phase in the presence of an aqueous solution of an inorganic acid or an inorganic acid and an organic acid at 40-150 deg.C (the first step), the reaction mixture of the first step is separated into an aqueous phase and an organic phase, and the aqueous phase is recycled to the first step. The organic phase is treated at 40-200 deg.C in the presence of the compound of formula and a carboxylic acid having a pka of <=4 (at 25 deg.C) (the second step), and the nuclear carboxylic acid is separated and recycled to the second step.
Inventors:
FUKUOKA SHINSUKE
WATANABE TOMOYA
WATANABE TOMOYA
Application Number:
JP21591182A
Publication Date:
February 07, 1989
Filing Date:
December 09, 1982
Export Citation:
Assignee:
ASAHI CHEMICAL IND
International Classes:
C07C269/00; B01J27/00; B01J31/04; C07B61/00; C07C67/00; C07C239/00; C07C271/16; C07C271/28
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