title: Synthesis and biological activity of a new class of insecticides: the N-(5-aryl-1,3,4-thiadiazol-2-yl)amides.
abstract: BACKGROUND
  Optimization studies on a high-throughput screening (HTS) hit led to the discovery of a series of N-(6-arylpyridazin-3-yl)amides with insecticidal activity. It was hypothesized that the isosteric replacement of the pyridazine ring with a 1,3,4-thiadiazole ring could lead to more potent biological activity and/or a broader sap-feeding pest spectrum. The resulting N-(5-aryl-1,3,4-thiadiazol-2-yl)amides were explored as a new class of insecticides.
  
  
  RESULTS
  Several methods for 2-amino-1,3,4-thiadiazole synthesis were used for the preparation of key synthetic intermediates. Subsequent coupling to variously substituted carboxylic acid building blocks furnished the final targets, which were tested for insecticidal activity against susceptible strains of Aphis gossypii (Glover) (cotton aphid), Myzus persicae (Sulzer) (green peach aphid) and Bemisia tabaci (Gennadius) (sweetpotato whitefly).
  
  
  CONCLUSIONS
  Structure-activity relationship (SAR) studies on both the amide tail and the aryl A-ring of novel N-(5-aryl-1,3,4-thiadiazol-2-yl)amides led to a new class of insecticidal molecules active against sap-feeding insect pests. © 2016 Society of Chemical Industry.
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Eckelbarger
authors.affiliation: Sealed Air, Charlotte, NC, USA.
authors.forename: Marshall H
authors.initials: MH
authors.lastname: Parker
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Maurice Ch
authors.initials: MC
authors.lastname: Yap
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Ann M
authors.initials: AM
authors.lastname: Buysse
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Babcock
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Ricky
authors.initials: R
authors.lastname: Hunter
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Yelena
authors.initials: Y
authors.lastname: Adelfinskaya
authors.affiliation: IUPUI Department of Chemistry, Indianapolis, IN, USA.
authors.forename: Jack G
authors.initials: JG
authors.lastname: Samaritoni
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Negar
authors.initials: N
authors.lastname: Garizi
authors.affiliation: Dow AgroSciences LLC, Indianapolis, IN, USA.
authors.forename: Tony K
authors.initials: TK
authors.lastname: Trullinger
mesh_terms: D000818:Animals; D001042:Aphids / Q000187:drug effects / Q000254:growth & development; D006430:Hemiptera / Q000187:drug effects* / Q000254:growth & development; D007306:Insecticides / Q000138:chemical synthesis / Q000494:pharmacology*; D009758:Nymph / Q000187:drug effects; D013329:Structure-Activity Relationship; D013830:Thiadiazoles / Q000138:chemical synthesis / Q000494:pharmacology
chemical_list: D007306:Insecticides; D013830:Thiadiazoles; C010852:2-amino-1,3,4-thiadiazole
keywords: cotton aphid Aphis gossypii; green peach aphid Myzus persicae; insecticide; insecticide discovery; sweetpotato whitefly Bemisia tabaci; thiadiazole