PURPOSE: To obtain the titled compound in high quality and yield without containing a metal, by purifying crude 3,3',4,4'-biphenyltetramine prepared by adsorbing 3,3'-dichloro-4,4'-diaminobiphenyl as a raw material on an adsorbent in a reducing atmosphere.
CONSTITUTION: Crude 3,3',4,4'-biphenyltetramine prepared by reacting 3,3'-dichloro-4,4'-diaminobiphenyl as a raw material in aqueous ammonia in the presence of a copper compound as a catalyst is washed with 30W40wt% aqueous ammonia and then water, and treated with hydrazine in an N2 gas stream. The atmosphere is adjusted to a deoxidizing and reducing atmosphere, and active carbon obtained by adsorbing iron chloride thereon as an adsorbent is present in the system. The crude 3,3',4,4'-biphenyltetramine is dissolved therein under stirring for 10W30min, and the resultant solution or suspension is filtered to afford crystals of the aimed purified compound, containing ≤0.1W0.2wt% copper and no other metal, and useful as a raw material for high polymer resins and synthetic fibers having improved heat resistance.
TAO KATSUTOSHI
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