| abstract |
Pyrazol derivatives having general formula (I) are disclosed, as well as their use as nitrification inhibitors. In said formula (I): residues R?1, R2, R3 and R4¿ may be substituted once or twice by halogen and/or hydroxyl; the residues R?1, R2 and R3¿ stand for halogen, nitro, hydrogen, C¿1?-C20-alkyl, C3-C8-cycloalkyl, C5-C20-aryl or alkyl aryl; and R?4¿ may stand for (a) a residue R4a of the formula (II), in which R?5 and R6¿ stand for hydrogen, C¿1?-C20-alkyl optionally substituted once or twice by halogen and/or hydroxyl, a carboxyl group, a carboxymethyl group or a functional derivative of both latter groups, and R?7¿ stands for a carboxyl residue or a carboxy-(C¿1?-C3-alkyl) residue or for a functional derivative of said groups, or R?4¿ may stand for (b) a residue R4b having the formula (III), in which R?8 and R9¿ stand for hydrogen, C¿1?-C20-alkyl, C2-C8-cycloalkyl, C5-C20-aryl or alkyl aryl, these residues being optionally substituted once or twice by halogen, and R?10¿ stands for hydrogen or a poly-(C¿2?-C4-alkylene oxide) residue whose terminal hydroxyl group may be etherified with an aliphatic C1-C10 alcohol or esterified with a C1-C10 carboxylic acid. |