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A kinetic study was carried out on the solvolysis of <i>o</i>-nitrobenzyl bromide (<i>o</i>-isomer, <b>1</b>) and <i>p</i>-nitrobenzyl bromide (<i>p</i>-isomer, <b>3</b>), and <i>o</i>-nitrobenzoyl chloride (<i>o</i>-isomer, <b>2</b>) in a wide range of solvents under various temperatures. In all of the solvents without aqueous fluoroalcohol, the reactions of <b>1</b> were solvolyzed at a similar rate to those observed for <b>3</b>, and the reaction rates of <b>2</b> were about ten times slower than those of the previously studied <i>p</i>-nitrobenzoyl chloride (<i>p</i>-isomer, <b>4</b>). For solvolysis in aqueous fluoroalcohol, the reactivity of <b>2</b> was kinetically more reactive than <b>4</b>. The <i>l/m</i> values of the extended Grunwald&#8722;Winstein (G&#8722;W) equation for solvolysis of <b>1</b> and <b>2</b> in solvents without fluoroalcohol content are all significantly larger than unity while those in all the fluoroalcohol solvents are less than unity. The role of the <i>ortho</i>-nitro group as an intramolecular nucleophilic assistant (internal nucleophile) in the solvolytic reaction of <b>1</b> and <b>2</b> was discussed. The results are also compared with those reported earlier for <i>o</i>-carbomethoxybenzyl bromide (<b>5</b>) and <i>o</i>-nitrobenzyl <i>p</i>-toluenesulfonate (<b>7</b>). From the product studies and the activation parameters for solvolyses of <b>1</b> and <b>2</b> in several organic hydroxylic solvents, mechanistic conclusions are drawn.