Gas-phase thermolysis of t-butylsulfenamides: N, N-dimethyl t-butylsulfenamide, 2,6-dimethylpiperidinyl t-butylsulfenamide, and N-t-butyl t-butylsulfenamide

✍ Scribed by Gonzalo Martin; Julian Ascanio; Jesus Rodriguez

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 392 KB
• Volume: 28
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1996)28:5<353::aid-kin4>3.0.co;2-u

✦ Synopsis

The arnide derivatives of t-butylsulfenic acid mentioned in the title have been thermolyzed in a stirred-flow reactor at temperatures of 273-390°C and pressures of 7-I 5 torr, using toluene as carrier gas, at residence times of 0 4-2 s. lsobutene formed in 95-99% yields, through order one reactions, following the Arrhenius equations-N.N-dirnethyl t-butylsulfenamide exp( -175 t 5 kl/mol RT) k(s-l) = 1014.45?U46 2.6-dimethylpiperidyl t-butylsulfenamide exp(-161 ? 3 kl/mol RT) k(s-l) = 101438'1126 N-t-butyl t-butylsulfenamide exp(-184 t 7 kl/molRT) k(s-l) = 1014.75"l.37

These thermolyses are considered to take place through unimolecular. four-center cyclic transition-state reaction mechanisms. giving rise to isobutene plus the corresponding S-unsubstituted thiohydroxylarnines. The latter decompose outside the reactor at temperatures above -78°C forming free sulfur and dirnethylamine. 2.6-dimethylpiperidine, and t-butylamine. respectively. 0