Gas-phase pyrolytic reactions of esters of 2-pyridine and 8-quinoline sulfonic acid

The rates of gas-phase thermal elimination reaction of esters of 2-pyridine sulfonic acid and 8-quinoline sulfonic acid have been measured over at least 50° for each compound. The relative rates of the first-order unimolecular decomposition at 500 K for the primary:secondary esters suggest that CO bond breaking is kinetically more significant than CH bond breaking, leading to a transition state of carbocationic character. This is consistent with the electron-donating effect provided by the methoxy substituent in 2-p-methoxyphenylethyl of 2-pyridine and 8-quinoline sulfonate esters stabilizing the carbocation center. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 771–775, 2000