| 摘要 |
Intermediates which are 1-piperazinecarboxylates or the general formula I (I) wherein R2, R3, R4, R5 are groups independently selected from hydrogen, lower alkyl having from 1 to 3 carbon atoms and phenyl, R6 is a group selected from hydrogen, F, C1, Br, lower alkoxy having from 1 to 3 carbon atoms and -CF3- -groups, R1 represents either an unsubstituted or substituted aryl group with good leaving group properties, suitably a phenyl or a para-nitro-phenyl group-, for producing 1-piperazinecarboxamides of the general formula II (II) wherein R7 and R8 are groups independently selected from the group of hydrogen, alkyl straight or branched chains having from 1 to 10 carbon atoms, cycloalkyl having from 3 to 8 carbon atoms, aralkyl having from 7 to 9 carbon atoms, alkenyl having from 3 to 10 carbon atoms or R7 and R8 represents together with the adjacent nitrogen atom a 4-7 membered ring such as wherein m = 0, 1, 2, 3, n = 1 or 2, and Ra is a group selected from lower alkyl having from 1 to 3 carbon atoms, hydroxy-loweralkyl having from 2 to 4 carbon atoms and a lower alkanoyl having from 1 to 3 carbon atoms, A process for preparing the carboxamides of formula II by reacting the 1-piperazinecarboxylates of formula I with an amine of formula III (III) wherein R7 and R8 are as defined above, is also described. |
