| 摘要 |
NEW MATERIAL:The benzothiazole derivative of formula I [R is phenyl (lower alkylthio) which may have lower alkylenedioxy group on the phenyl ring, or group of formula II (R<1> and R<2> are H, lower alkyl, halo(lower alkyl), etc., or R<1> and R<2> may together with bonded N atom form a 5- or 6-membered saturated heterocyclic group which may contain additional O or N atom); A is lower alkylene] and its salt. EXAMPLE:6-[2-(4-Acetyl-1-piperazinyl)acetyl]-2-benzothiazolone. USE:It has the activity to increase the contraction of cardiac muscle (positively inotropic activity) and to increase the coronary blood flow rate, and is useful as a cardiotonic agent for the remedy of cardiac diseases such as congestive heart. PREPARATION:The compound of formula I can be produced by reacting the compound of formula III (X<2> is halogen) with the compound of formula RH at room temperature -200 deg.C, preferably room temperature -120 deg.C. |
