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Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.46A [2007] >
IJC-A Vol.46A(06) [June 2007] >
| Title: | Kinetics and mechanism of the nucleophilic ring opening of oxazolinone in mixed aqueous solvents |
| Authors: | Ismail, Amel M |
| Issue Date: | Jun-2007 |
| Publisher: | CSIR |
| Abstract: | Solvent effect on the kinetics of ring opening of oxazolinone has been investigated in neutral and alkaline medium in dioxan-water mixtures up to 50% v/v in the temperature range of 40-60ºC. The thermodynamic activation parameters have been calculated and discussed in terms of solvation effect. The isokinetic temperature in both media (310, 303 and 298 K for neutral, alkaline hydrolysis by NaOH and Na₂CO₃ respectively) indicates that the reaction is entropy controlled and that solute-solvent interactions play an important role. The correlation of logk₂ against either Grunwald-Wientien Y values or log[H₂O] was found to be linear, while the correlation between logk₂ and the reciprocal of the dielectric constant was non-linear. The estimated value of the slope m in Grunwald relationship gives a value less than unity indicating SAN/SN² mechanism. Mechanism for the oxazolinone ring opening has been proposed. |
| Page(s): | 916-922 |
| ISSN: | 0376-4710 |
| Source: | IJC-A Vol.46A(06) [June 2007]
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