Rates and Products of Reactions of N-Benzoyloxy-2-nitrobenzenamine with Metal Alkoxides

Abstract

A major pathway when N-benzoyloxy-2-nitrobenzenamine (1b) reacts with sodium methoxide is attack on carbonyl and production of methyl benzoate. In a competing pathway, proton abstraction is followed by loss of benzoate and formation of 2,1,3-benzoxadiazole N-oxide (4). With the more bulky t-butoxide base, only the latter pathway is followed, though the heterocyclic product undergoes subsequent destruction. Both the detection in the visible spectrum of a red transient intermediate, and a lack of an electron spin resonance spectrum, indicate it to be the anion (2b). The rates of the reactions of potassiumt-butoxide with (1b) and N-benzoyloxy-4-nitrobenzenamine (7) are very similar, which rules out the possibility that the ortho-nitro group in (1b) provides neighbouring group assistance for loss of benzoate ion from the anion (2b).

Rate measurements show that the loss of benzoate from (2b) is 39 times slower than chloride loss from the analogous anion (2a).