Synthesis of isotope-labeled D5-cypermethrin

D5-Cypermethrin was synthesized with D6-phenol (98% atom D) as labeled precursor. D6-Phenol was dehydrated by potassium deuterium oxide in anhydrous toluene, and then reacted with 3-bromobenzaldehyde in the presence of catalytic amount of cuprous chloride to obtain a key labeled intermediate D5-3-phenoxy-benzaldehyde through Ullmann condensation reaction. Finally, D5-cypermethrin was obtained by phase transfer catalysis cyanohydrins reaction using D5-3-phenoxy-benzaldehyde, sodium cyanide and 3-(2, 2-dichlorovinyl)-2, 2-dimethylcyclopropanecarbonyl chloride as raw materials by one-step method. The yield based on the amount of substance of D6-phenol was 19.5%. The structure of target product was confirmed by MS, NMR and HPLC. Its chemical purity was higher than 98%, and isotopic abundance was higher than 98% (atom D). This key labeled intermediate could also be used to synthesize other labeled pyrethroids. © 2020, Editorial Office of FINE CHEMICALS. All right reserved.