Research Of Dibenzo Cyclohepten Containing Fluorine As Rodenticides

Highly selective rodenticides with high-toxic have always been an important issue.The killing of rattus norvegicus accounts for 80%of urban rodent controlling work.N-piperidinedibenzocycloheptene has been used to kill Rattus norvegicus for several years,which has high selectivity and is safe for non-target animals.However,this rodenticide has been discarded,because its effect for different kinds of individuals is so unstable and its toxicity is relatively low.Previous research has found that attaching halogens to appropriate positions of the benzene ring of such compounds can enhance its toxicity.And the improvement of toxicity for this kind of compounds would be varying with different kinds of halogens and the position of halogenating.In this paper,two new different rodenticides including CF3 or F were synthesized,which were including CF3 or F and based on dibenzocycloheptanone.Toxic and selectivity of two synthesized rodenticides were tested.The sulfonation reaction on the benzene was carried out using dibenzocycloheptanone as a raw material.The main product was M1-1 by controlling the conditions of the sulfonating reagent,the reaction temperature,and the concentration.Bromination reaction was then carried out on M1-1.Bromine was replaced by CF3 after the sulfonic acid group was hydrolyzed,obtaining M1-4 including CF3 attached to the benzene ring directly.M1-4 was reduced to trifluoromethylated dibenzocycloheptanol with sodium borohydride,and the hydroxyl group was converted into chlorine by using thionyl chloride as a chlorinating reagent.The chlorine was replaced with piperidine to obtain the product.R1 was obtained from purified the product.The first step of synthesis of another new rodenticide which include F w that the nitration on the benzene was carried out using dibenzocycloheptanone as a raw material.Further,preparation of intermediate M2-7 by reduction reaction,diazotization reaction and fluorination.Similar to the synthesis of R1,M2-7 was reduced to fluorinated dibenzocycloheptanol with sodium borohydride,and the hydroxyl group was converted into chlorine by using thionyl chloride as a chlorinating reagent.The chlorine was replaced with piperidine to obtain the product.R2 was obtained from purified the product.The chemical structures of all synthetic compounds were characterized by FT-IR and 1H-NMR.The results showed that the target compounds were synthesized.The feeding coefficient and the acute oral toxicity LD50 were tested for R and the synthesized R1,R2.The results showed that R1 and R2 had good palatability.Compared with R,the toxicity of R1 and R2 totally were improved.Besides,R2 was more toxic than R1.The high selectivity was showed by R1 and R2 were toxic to Rattus norvegicus and low-toxic to white mouse.And the selectivity of R2 was higher.Compared with other similar synthesized rodenticides by other colleagues,the results showed that the order of improvement of the toxicity of rattus norvegicus was R2>R1>Chloride>Bromocide>R,R1 had highest selectivity among these five compounds.In summary,the newly synthesized trifluoromethylated rodenticide R1 and fluorinated rodenticide R2 have greater toxicity to the rattus norvegicus and has good palatability while retaining the high selectivity of the parent.Compared with other similar synthesized rodenticides,trifluoromethylated rodenticide R1 is the most selective,which is safe for non-target animals.Fluorinated rodenticide R2 is the most toxic,which takes least time to kill rodents.And more rodents are killed at similar time.In a word,R1 and R2 are more excellent and highly selective rodenticide.