Synthesis and Structure-Activity Relationships for the Fungicidal Activity of O , O -bisaryl sec -butylphosphonates

✍ Scribed by Sanyal, Doyeli; Roy, Nripendra K.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 210 KB
• Volume: 50
• Category: Article
• ISSN: 1526-498X
• DOI: 10.1002/(sici)1096-9063(199706)50:2<85::aid-ps576>3.0.co;2-e

✦ Synopsis

Sixteen O,O-bisaryl sec-butylphosphonates have been synthesised by condensing sec-butylphosphonyl dichloride with substituted phenols. The compounds were tested against two phytopathogenic fungi, Rhizoctonia bataticola and Helminthosporium oryzae. The most active compound against R. bataticola is O,O-bis(3-methylphenyl) sec-butylphosphonate 29É56 mg litre~1) and (ED 50 against H. oryzae, O,O-bis(2-chlorophenyl) sec-butylphosphonate and its parachloro analogue 0É14 and 0É13 mg litre~1 respectively). Quantitative (ED 50 structureÈactivity relationships on the fungicidal activity have been analysed by means of multiple regression analysis using physicochemical substituent parameters. Electronic parameters viz., p and F have expressed signiÐcant variability in fungitoxicity against both the fungi, viz. R. bataticola and H. oryzae. Hydrophobic and steric parameters are also found to be important in the correlation studies.