title: Synthesis and bioefficacy evaluation of new 3-substituted-3,4-dihydro-1,3-benzoxazines.
abstract: A new series of 1, 3-Benzoxazines were synthesized, characterized ((1)H NMR and (13)C NMR) and evaluated for their pesticidal activity. Six new 3-alkyl-3, 4-dihydro-4-methyl-2H-1, 3-benzoxazines (1-6) were prepared by hydroxymethylation of secondary amines with formaldehyde in 65-68% yields. These compounds were screened for there IGR activity against Spodoptera litura and for antifungal fungal activity in vitro against Sclerotium rolfsii ITCC 6181 by poisoned food technique. Insect Growth Regulatory (IGR) activity against Spodoptera litura showed that compound 3-Nonyl-3,4-dihydro-4-methyl-2H-1,3-benzoxazines was most effective as IGR with larval GI(50) of 1.863 mu g/Insect. Compounds 3-Octyl-3,4-dihydro-4-methyl-2H-1,3-benzoxazines and 3-Decyl-3,4-dihydro-4-methyl-2H-1,3-benzoxazines were effective IGRs. Antifungal screening revealed that compound 3-Dodecyl-3, 4-dihydro-4-methyl-2H-1,3-benzoxazines, was highly effective against Sclerotium rolfsii with LC(50) value 31.7 mg L(-1) comparable with commercial fungicide Hexaconazole (LC(50) 1.27 mg L(-1)). Also compounds 3-Nonyl-3, 4-dihydro-4-methyl-2H-1,3-benzoxazines and 3-Decyl-3,4-dihydro-4-methyl-2H-1,3-benzoxazines displayed promising fungitoxicity. The results described in this paper are promising and provides new array of synthetic chemicals to be utilized as pesticides.
authors.affiliation: Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi, India. iamshakil@gmail.com
authors.forename: Najam A
authors.initials: NA
authors.lastname: Shakil
authors.forename: Alka
authors.initials: A
authors.lastname: Pandey
authors.forename: Manish K
authors.initials: MK
authors.lastname: Singh
authors.forename: Jitendra
authors.initials: J
authors.lastname: Kumar
authors.forename: Satish K
authors.initials: SK
authors.lastname: Awasthi
authors.forename: Chitra
authors.initials: C
authors.lastname: Srivastava
authors.forename: Mukesh K
authors.initials: MK
authors.lastname: Singh
authors.forename: Ravi P
authors.initials: RP
authors.lastname: Pandey
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D001487:Basidiomycota / Q000187:drug effects*; D048588:Benzoxazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D007605:Juvenile Hormones; D009682:Magnetic Resonance Spectroscopy; D010575:Pesticides / Q000138:chemical synthesis* / Q000737:chemistry / Q000633:toxicity*; D018411:Spodoptera / Q000187:drug effects*
chemical_list: D000935:Antifungal Agents; D048588:Benzoxazines; D007605:Juvenile Hormones; D010575:Pesticides