Hydrolytic stability and pesticidal activity of N'-methyl- and N'-arylcarbamates of 3-(N,N-diethylamino)phenol

Abstract

Twelve carbamates based on 3-(N,N-diethylamino)phenol have been prepared, and their hydrolysis rate in aqueous media of pH 7-12.5, their inhibition of butyrylcholin esterase and acetylcholin esterase and herbicidal activity have been studied. The hydrolysis of the compounds studied in the mentioned media proceeds by the ElcB mechanism, the value of reaction constant at 25 °C is ρ = 1.12 ± 0.08. The hydrolysis rate in the pH region 7-8.5 is affected by protonation of the 3-N,N-diethylamino group. The compounds I-XII inhibit butyrylcholin esterase (pI50 value 5.1-6.5). Acetylcholin esterase is inhibited most efficiently by the carbamates XII (pI50 = 8.3), XI (pI50 = 6.25) and VII (pI50 = 5.07). Herbicidal effects are small, the effective dose being above 5 kg/ha.