The invention relates to a preparation method of
cycloxaprid. The preparation method comprises steps as follows: (1), concentrated
sulfuric acid is added to a reaction kettle A,
guanidine nitrate is added, and the mixture is heated to 40-42 DEG C and reacts for 30-40 min; (2), after the reaction,
nitroguanidine as an intermediate is obtained through ice
hydrolysis, cooling and filtering; (3),
acetonitrile as a
solvent,
paraformaldehyde and
nitroguanidine obtained in the step (2) are added to a reaction kettle B in sequence, stirred uniformly and heated to 80-85 DEG C, 2-chloro-5-chloromethylpyridine is dropwise added to a
reaction system slowly, and the temperature is controlled to be lower than or equal to 80 DEG C; (4), after 2-chloro-5-chloromethylpyridine is dropwise added, the temperature is preserved for 8-10 h under a temperature
system lower than or equal to 80 DEG C; (5), after the reaction, cooling is performed, solids are filtered out, and
cycloxaprid is obtained after
drying. The preparation method of
cycloxaprid has the advantages as follows: purity of the cycloxaprid product can be guaranteed, and yield of the cycloxaprid product can be increased.