Antihypertensive 3-substd.-6-pyrazolyl-pyridazine derivs. - inhibitors of prostaglandin catabolism

摘要

Pyrazole derivs. of formula (I) and their addn. salts with pharmaceutically acceptable acids are new: In the formula, R1 is H, 1-6c alkyl, 2-4C hydroxyalkyl, or 3-6C cycloalkyl or phenyl; R2 is H, F, Cl, Br, 1-6C alkyl, 2:4C hydroxyalkyl, NO2 or NR5R6; R5 and R6 are each H, 1-4C alkyl or 2-4C hydroxyalkyl. R3 is as R1 or also Cl, OH, NH2, or OCH3; R4 is CONH2, CN, NR7.NHT8 or NR9R10; R7 and R8 are each H, 1-4C alkyl, 2-4C hydroxyalkyl or 1-4c alkoxycarbonyl; and R9 and R10 = H, 1-5C alkyl, 2-4C hydroxyalkyl, 3-6C cycloalkyl, phenyl or benzyl, or NR9R10 is morpholino, piperidino or piperzino. (I) are prepd. e.g. by reactng corresp. 3-chloro cpds. with HNR7.NHR8 or HNR9R10. (I) are useful for treating renal hypertension. They inhibit the activity of prostaglandin-catabolising enzymes so increase the concnn. of endogenous PG's.