Diphenylamine prodn by heating aniline - in presence of complex salt contg boron, fluorine, oxygen and nitrogen as catalyst

摘要

Prodn. of diphenylamine by heating aniline at 300-360 degrees C under a press. of 10-40 atm. in the liquid phase in the presence of a complex salt of boron as a catalyst is improved using a catalyst of formula: R1(OH)2BF2 (in which R1 is NH4 or C6H5NH3) or R2OB4R12 (in which R2 is 2NH4 or 2C6H5NH3 or C6H5NH3.NH4). The catalyst is used in an amt. of 0.5-4% w.r.t the weight of aniline. Diphenylamine is used in large quantities in the prodn. of dyes, phenothiazine or nitrosodiphenylamine, and also as a stabiliser for nitrocellulose gum powders. The use of the above catalyst results in high yields (98% theoretical); there is no significant formation of by-products. The catalyst is not destroyed during the process and does not lose its high activy (in contrast to complex salts of BF3 used for this purpose heretofore). High quality product is obtd. (purity 99.5-99.8%; m.pt. 54 degrees C.). The catalyst is non-corrosive.