申请人:THE DOW CHEMICAL COMPANY
公开号:EP0065025A1
公开(公告)日:1982-11-24
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°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:
and
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.
本发明涉及一种在催化剂存在下由有机碳酸盐和芳香胺制备氨基甲酸酯的工艺。8;(3) 锌或二价锡或二价钴或三价钴盐;(4) 具有 5 至 10 个碳原子的 1,3-二酮的二价钴或三价钴盐;(5) 式 I 和 II 所代表的四价烷基锡化合物或四价烷基锡氧化物:
和
其中每个 R 独立地为具有 1 至 10 个碳原子的烃基,或具有 2 至 10 个碳原子的羧基,X 为卤素原子,x 的平均值为 1 至 5,y 的平均值为 1 至 4;以及 (6) 选自碳酸锌、硫化锌和氧化锌的无机锌化合物。