| 摘要 |
1340936 Isocyanates MAGYAR TUDOMANYOS AKADEMIA 29 April 1971 12167/71 Heading C2C Organic isocyanates are produced by reacting a primary amine and/or a salt thereof and phosgene in an inert solvent using an acid amide which has at least one N-substituent or a secondary amine as catalyst in an amount of from 0À1 to 10% by wt. The acid amide preferably has the formula R 1 -CO-NR 2 R 3 wherein R 1 is hydrogen, a dialkylamino group or an N- linked saturated nitrogen-containing heterocyclic group, R 2 is a hydrogen atom, in which case R 3 is an alkyl group, or R 2 and R 3 are each alkyl groups or together with the adjacent nitrogen atom form a saturated heterocyclic ring. The secondary amine preferably has the formula R 4 -NH-R 5 or wherein R 4 and R 5 are alkyl, aralkyl or cycloalkyl and n is an integer of from 1 to 7. |
