| 摘要 |
NEW MATERIAL:The compound of formula I (R1-R3 are H, OH or <=5C alkoxy or two of R1-R3 together form the group of formula IV or formula V; n is 0- 4; the dotted line represents single or double bond) or its salt. EXAMPLE:6-{4-[4-( 2, 3, 4-Trimethoxybenzyl )-1-piperazinylcarbonyl]phenyl}-4, 5- dihydro-3(2H)-pyridazinone. USE:A cardiotonic having high activity and exhibiting the activity sufficiently for a long period. The salt of the compound has also vasodilating effect. PREPARATION:The compound of formula I can be prepared by reacting the carboxylic acid of formula II with an alkylhalocarboxylic acid to obtain a mixed acid anhydride, and carrying out the conventional amide-bond formation reaction by reacting the anhydride with an amine of formula III in a mixture of dimethylamide and tetrahydrofuran, etc. in the presence of a basic compound such as triethylamine. |
