| 摘要 |
A method for preparing N,N'-substd. urea of formula (I) comprises reacting mono-nitro cpd., aromatic primary amine and CO in the presence of a Pd cpd. as a main catalyst and an ammonium salt or a phosphonium salt containing halogen atoms as an auxiliary catalyst, and a nonpolar solven. In (I), Ar1 and Ar2 each = aromatic gp. opt. substd. by halogen, alkyl or alkoxy. Pref. the Pd cpd. is PdC12, PdBr2, PdI2, Pd(NO3)2, PdSO4, Pd(OCOCH3)2, Pd(OCOCF3)2, PdX2L2 (X = halogen, NO3, OCOCH3, OCOCF3; L=PR3 (R = methyl, ethyl or butyl) or PPh3; the ammonium salt is tetraethyl ammonium chloride, tetramethyl ammonium bromide, etc.; the phosphonium salt is tetrabutyl phosphonium bromide, tetramethyl phosphonium chloride, etc.
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