Herbicide and plant-nematocide based on mercaptonicotinic acid derivative

PURPOSE: To obtain a herbicide and a plant-nematocide having strong activity against weeds and nematodes living in plants, comprising a specific mercaptonicotinic acid derivative. CONSTITUTION: This herbicide and a plant nematode comprise a mercaptonicotinic acid derivative of formula I [(n) is 0-3; R 1 is H, a halogen, an alkyl, a halogenoalkyl or a (substituted) phenyl; R 2 is an alkyl, an alkenyl, an alkynyl, an aryl, etc.; R 3 is a halogen, cyano, nitro, an alkyl, an alkoxy, etc.] (e.g. a compound of formula II). The herbicide and the plant nematode are obtained by formulating the mercaptonicotinic acid derivative of formula I with an extender and a surfactant. The compound of formula I is obtained, for example, by reacting a mercaptonicotinic acid halide of formula III (X 1 is a halogen) with an amino compound of formula IV. COPYRIGHT: (C)1993,JPO