Mechanistic Study of Chloro - Xylenyl Phosphate Resisting Hydrolysis at Low Temperature

Shashi Kala Pandit and Shashi Prabha

¹Government Post Graduate College, Shahdol India.

²School of Studies in Chemistry, Jiwaji University, Gwalior - 474011 India.

ABSTRACT:

The hydrolysis of the highly stable mono-4-chloro-2,6-dimethylphenyl hydrogen phosphate has been kinetically pursued in the acid medium, 0.1 to 7.0 M-H CI at 90 °C in the aqueous phase. The ester exhibits typical features like: (i) an optimum rate at the usual 4.0M, HCI. (ii) first order rate-coefficients in substrate, (iii) the sole presence and contribution of the conjugate acid form, with specific acid catalysis, (iv) P-O bond fission, and(v) SN2 (P) pathway involving a transition state, justified by Arrhenius parameters etc. Insptte of showing the negative salt effect, the reactivity is promoted by Ca .65 times incomparison to the similarly-substituted 2,4,6-trichiorophenyI phosphate. This aspect is explained in terms of +1 effect and no-bond resonance of the two-o-Me-substituents, This monoester differs from the related di-and tri-esters which both exhibit zero order rate-coefficients. The highest rates of this monoester are attributed to the steric acceleration of the two ortho-alkyI groups in the arylmatnx.

KEYWORDS:

Hydrolysis; Chloro - Xylenyl; Hydrolysis; Temperature

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Copy the following to cite this article: Pandit S. K, Prabha S. Mechanistic Study of Chloro - Xylenyl Phosphate Resisting Hydrolysis at Low Temperature. Orient J Chem 1997;13(2).

Copy the following to cite this URL: Pandit S. K, Prabha S. Mechanistic Study of Chloro - Xylenyl Phosphate Resisting Hydrolysis at Low Temperature. Orient J Chem 1997;13(2). Available from:http://www.orientjchem.org/?p=37411