| 摘要 |
T 108 PROCESS FOR THE PREPARATION OF UREA DERIVATIVES AND CATALYST SYSTEM The invention relates to a process for the preparation of urea derivatives of the general formula (I) wherein R is an alkyl group and X is a halogen atom, an alkyl-, alkoxy-, aryloxy-, cyano-, ester- or trifluoromethyl group and n is from 0 to 5, which comprises reacting an aromatic nitro compound of the general formula (II) wherein X and n are as defined above with carbon monoxide and an amine HNR2 wherein R is an alkyl group, in the presence of a catalyst system comprising (a) 8 group VIII noble metal or a compound thereof, (b) a bidentate ligand and (c) an acid having a pKa of more than 2 or a transition metal salt of said acid. EIRH04 |
