N-Phenylpyrazole derivatives of the formula: ##STR1## wherein R.sup.1 represents cyano, nitro, halogen, acetyl or formyl; R.sup.2 represents R.sup.5 SO.sub.2, R.sup.5 SO or R.sup.5 S in which R.sup.5 is optionally halogen substituted alkyl, alkenyl or alkynyl; R.sup.3 represents a hydrogen atom or a group NR.sup.6 R.sup.7 wherein R.sup.6 and R.sup.7 each represent hydrogen, alkyl, alkenylalkyl, alkynylalkyl, formyl, optionally halogen substituted alkanoyl, optionally halogen substituted alkoxycarbonyl, or alkoxymethyleneamino, halogen, or R.sup.6 and R.sup.7 together form a cyclic imide and R.sup.4 represents a substituted phenyl group possess arthropodicidal, plant nematocidal, anthelmintic and anti-protozoal properties; their preparation, compositions containing them and their use are described.
4-Nitro-N-phenylpyrazole derivatives of the formula:
wherein R¹ represents fluorine, chlorine or bromine, R² represents chlorine or bromine, or alkyl or alkoxy group optionally substituted by halogen, R³ is as defined for R¹ or represents hydrogen, R⁴ represents halogen, cyano or nitro, R⁵ represents hydrogen, an amino group -NR⁶R⁷ wherein R⁶ and R⁷, each represents hydrogen, alkyl, formyl, alkanoyl (or R⁶ and R⁷ together form a cyclic imide) which may be unsubstituted or substituted by halogen, alkoxycarbonyl which may be unsubstituted or substituted by halogen, or R⁵ represents alkoxymethyleneamino which may be unsubstituted or substituted on methylene by alkyl, or represents fluorine, chlorine, bromine or iodine possess pesticidal properties; their preparation and use, and compositions containing them are described.