KINETICS AND MECHANISM OF PYROLYSIS OF SULFONYL HYDRAZONES AND OXIMES- PART 1 - CONTRIBUTION TO REACTIVITY FROM HYDRAZONE HN-N AND OXIME O-N BOND POLARITY

Rates were obtained for the pyrolysis of tosyl arenecarboxaldehyde hyd razones (1-5), and mesyl benzaldoxime (6). The substituted tosyl sulph onamides (TsHNN=CHAr: 1-5) and the mesylate (6) gave in a novel pyroly tic reaction the following Arrhenius log A/s(-1) and E-a/kJ mol(-1) va lues, respectively: 12.70 and 157.7 (1, Ar = C6H5), 12.29 and 152.6 (2 , p-NO2CbH4), 11.85 and 148.2 (3, m-NO2C6H4), 12.17 and 152.0 (4, p-Cl C6H4), 11.01 and 140.8 (5, p-CH3OC6H4), and 12.96 and 109.9 for (6). T osyl benzaldoxime (7) was also studied. The reactions yielded cyanoare nes together with sulphonic acids from 6 and 7, and p-methylbenzenesul phonamide from compounds 1-5. (C) 1998 Published by Elsevier Science L td. All rights reserved.