| 摘要 |
<p>This invention is directed to a process for preparing carbamates from an organic carbonate and an aromatic amine in the presence of a catalyst. The reaction is conducted at a temperature of at least 200 DEG C and the catalyst is at least one member selected from the group consisting of (1) zinc or divalent tin salts of monocarboxylic acids having a pKa value of less than 2.8 other than such salts of trifluoroacetic acid; (2) divalent cobalt or trivalent cobalt salts of monocarboxylic acids having a pKa value of less that 2.8; (3) zinc or divalent tin or divalent cobalt or trivalent cobalt salts of organic materials having more than one -COOH group per molecule; (4) divalent cobalt or trivalent cobalt salts of a 1,3-diketone having from 5 to 10 carbon atoms; (5) tetravalent alkyl tin compounds or tetravalent alkyl tin oxides represented by formulas I and II: <CHEM> wherein each R is independently a hydrocarbon group having from 1 to 10 carbon atoms, or a carboxylate group having from 2 to 10 carbon atoms, X is a halogen atom, x has an average value of from 1 to 5, and y has a value of from 1 to 4; and (6) an inorganic zinc compound selected from zinc carbonate, zinc sulfide, and zinc oxide.</p> |
