79235-34-0Relevant academic research and scientific papers
Chromone fungicides
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, (2008/06/13)
Compounds of the formula where one of Z and Y is CO and the other is C-W-R2 and the dotted line indicates a double bond is present where necessary to meet valency requirements, W is O, S(O)n, N(R3), N(R3)(R4), N(R3)O or ON(R3); R1 is hydrogen, or an optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, phenyl or heterocyclyl group; R2, R3 and R4, which may be the same or different, are as defined above for R1, or are acyl, or R2 and R3 or R2 and R4 or R3 and R4 together with the nitrogen or oxygen to which they are attached form an optionally substituted ring which may contain other hetero atoms; each X, which may be the same as or different from any other X, is halogen, CN, NO2, SF5, B(OH)2, triakylsilyl or a group E, OE or S(O)nE where E is a group as defined hereinbefore for R2 or is optionally substituted amino; or two adjacent groups X together with the atoms to which they are attached form an optionally substituted carbocyclic or heterocyclic ring; n is 0, 1 or 2; and p is 0 to 4 have fungicidal activity. Many of the compounds are novel.
Alkaline Hydrolysis of Aryl Phenylacetates and Aryl 4-Nitrophenylacetates. Evidence consistent with an Elimination-Addition Mechanism
Chandrasekar, Ramamurthy,Venkatasubramanian, Nagaswami
, p. 1625 - 1632 (2007/10/02)
Hydrolysis of the substituted phenyl esters of phenylacetic acid is found to be first order each in the ester and hydroxide ion.Hydrolysis is catalysed by general bases and the catalytic coefficients for the substituted phenoxides obey the Broensted relation with β +0.49.The rate of hydrolysis of the esters of 4-nitrophenylacetic acid is independent of in the range employed.Both series of reactions exhibit low solvent isotope effect and high sensitivity to substituents in the leaving group .These datasuggest an E1cB mechanism for the hydrolysis.The keten intermediate envisaged for such a mechanism has been trapped as the anilide when the reactions are conducted in aniline buffers, without any effect on the rate of hydrolysis for variations in .An increase in the DMSO content in the solvent decreases the rate of hydrolysis of the esters of 4-nitrophenylacetic acid, which is explained by an (E1cB)anion mechanism for the hydrolysis.Transfer to aqueous DMSO results in rate accelerations for the esters of phenylacetic acid which can be accounted for by either an (E1cB)Bion pair or (E1cB)reversible mechanism for the hydrolysis.
