Process for preparing pyrazoles

eÜen poskytuje · innou synt zu pyrazol , vhodnou k bezpe n mu zaveden zp sobu ve velk m m ° tku a zvl Üt pro synt zu proveditelnou v jedn n dob . eÜen se t²k zp sobu p° pravy pyrazol obsahuj c kroky, kter²mi jsou tvorba 4-halogenfenyl-butan-1,3-dionu (nebo jeho keto-enol tautomeru) a reakce uveden ho dionu s benzensulfonamidem za vzniku [3-halogenalkyl-1H-pyrazol-1-yl]benzensulfonamidu.\ The present invention provides an efficient synthesis of pyrazoles suitable for adoption in a safe, large-scale process and particularly for synthesis that can be carried out in a single vessel. The invention relates to a process for preparing pyrazoles comprising the steps of forming a l-aryl-4-halobutane-1,3-dione and reacting said dione with an aminosulfonylphenyl hydrazine, or salt thereof, to form the [3-haloalkyl-lH-pyrazol-l-yl] benzenesulfonamide.