New 6-(4-sulfonamido-phenyl)-5-methyl-dihydropyridazinones, having erythropoietin sensitizing and erythropoiesis stimulating activity, useful for treating anemia

摘要

6-(4-Sulfonamido-phenyl)-5-methyl-dihydropyridazinone derivatives (I) are new. Pyridazinone derivatives of formula (I) (including their tautomers and salts) are new. A, D, E, G = H, alkyl, OH, CF3, halo or alkoxy; R1, R2 = H or alkyl; R3 = 1-8C alkyl; aryl or Het (both optionally substituted by 1-3 of halo, CF3, NO2, OH, COOH, alkyl, alkoxy, alkoxycarbonyl, 1-6C acyl, Het, OR4 or -(CH2)a-NR5COR6); or 1,2,3,4-tetrahydro-6-naphthyl or a heterocyclic group of formula (i)-(iii); Het = 5-6 membered aromatic heterocycle, containing 1-3 O, S and/or N as heteroatom(s); R4 = aryl (optionally substituted by 1-3 of halo, NO2, CF3 or alkyl); a = 0-2; R5 = H or 1-4C alkyl; R6 = alkyl or aryl (optionally substituted by 1-3 of halo or alkyl); R7, R8 = halo (preferably Cl); unless specified otherwise alkyl moieties have 1-6C and aryl moieties 6-10C. An Independent claim is included for the preparation of (I).