title: Microwave synthesis, characterization, and bio-efficacy of novel halogenated Schiff bases.
abstract: A new series of halogenated Schiff bases was synthesized by the condensation of 5-fluoro-2-hydroxy acetophenone and 3,5-dichloro-2-hydroxy acetophenone with different alkyl amines, namely propyl, pentyl, hexyl, heptyl, octyl, nonyl, dodecyl, tetradecyl, hexadecyl, and octadecyl amines, under microwave irradiation. Newly formed molecules were characterized by Infrared and nuclear magnetic resonance ((1)H NMR and (13)C NMR) spectroscopic techniques. Further, the Schiff bases were screened for antifungal bioassay, and the results showed potential fungicidal activity against two very important plant infecting fungi, viz. Rhizoctonia solani and Sclerotium rolfsii. Among the screened compounds, 2,4-dichloro-2-[1-(propylimino)ethyl]phenol was found to be the most active compound against both R. solani (ED50 8.02 mg L(-1)) and S. rolfsii (ED50 21.51 mg L(-1)) followed by 2,4-dichloro-2-[1-(pentylimino) ethyl]phenol (ED50 13.02 and 29.57 mg L(-1), respectively). The synthesized compounds were also screened for antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging technique. All the compounds showed very low to moderate activity as compared with Gallic acid.
authors.affiliation: a Division of Agricultural Chemicals, Indian Agricultural Research Institute , New Delhi , India.|b School of Vocational Studies and Applied Sciences, Gautam Buddha University , Greater Noida , Uttar Pradesh , India.
authors.forename: Braj B
authors.initials: BB
authors.lastname: Singh
authors.affiliation: a Division of Agricultural Chemicals, Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Najam A
authors.initials: NA
authors.lastname: Shakil
authors.affiliation: a Division of Agricultural Chemicals, Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Jitendra
authors.initials: J
authors.lastname: Kumar
authors.affiliation: a Division of Agricultural Chemicals, Indian Agricultural Research Institute , New Delhi , India.
authors.forename: Virendra S
authors.initials: VS
authors.lastname: Rana
authors.affiliation: b School of Vocational Studies and Applied Sciences, Gautam Buddha University , Greater Noida , Uttar Pradesh , India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Mishra
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry*; D001203:Ascomycota / Q000187:drug effects*; D001713:Biphenyl Compounds / Q000737:chemistry*; D054879:Halogenation / Q000187:drug effects*; D009682:Magnetic Resonance Spectroscopy; D008872:Microwaves; D012232:Rhizoctonia; D012545:Schiff Bases / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D001713:Biphenyl Compounds; D012545:Schiff Bases
keywords: 3,5-dichloro-2-hydroxyacetophenone; 4-fluoro-2-hydroxyacetophenone;; Fungicidal; Schiff base; microwave