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Indian Journal of Chemistry -Section A (IJC-A) >
IJC-A Vol.46A [2007] >
IJC-A Vol.46A(03) [March 2007] >
| Title: | The kinetic study on the effects of mixed aqueous-organic solvents on the rate of O- and N- cyclisation of N-(4'-nitrophenyl)phthalamic acid |
| Authors: | Ahmad, Wan Hamdah Wan
Ariffin, Azhar
Khan, M Niyaz |
| Issue Date: | Mar-2007 |
| Publisher: | CSIR |
| Abstract: | The pseudo-first-order rate constants (kobs) for the intramolecular carboxylic group-assisted cleavage of
N-(4'-nitrophenyl)phthalamic acid (1) show nonlinear decrease of ~ 17-fold and ~ 117-fold with the increase in the respective contents of CH3CN (10-80% v/v) and 1,4-dioxan (9.5-79.4% v/v) in mixed aqueous solvents. The fraction of N-cyclization of 1 leading to the formation of N-(4'-nitrophenyl)phthalimide, 2, remains almost zero at ≤40% v/v CH₃CN while it increases from 0.06 to 0.49 with increase in CH₃CN content (50-80% v/v) at 1.0×10⁻³ M HCl. However, the observed data reveal an almost absence of N-cyclization within 1,4-dioxan content range 10-80% v/v. |
| Page(s): | 416-421 |
| ISSN: | 0376-4710 |
| Source: | IJC-A Vol.46A(03) [March 2007]
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