As part of our ongoingproject on sulfonyl derivatives as bioactive heterocyclic compounds, ourresearch has been focused on exploring the consequences of an N?SO₂?Rlinkage on the stereoelectronic properties of somesulfonyl-tetrahydroquinolines.¹

In this case, we areinterested in the reactivity of some trifluoromethyl sulfonyl-dihydropyridines²and how the trifluoromethanesulfonic moiety can be removed. Here, we describe acomparison of three methodologies: static gas phase pyrolysis, microwaveinduced pyrolysis (MIP) and photolysis reactions of these non-aromaticcompounds, scheme 1. We demonstrated that it is possible to achieve therearomatization process by elimination of the trifluoromethyl sulfonyl moietythrough the three processes, being the static pyrolysis the best method toobtain the desired compounds. In turn, the products proved to be substitutedpyridines that are known to be difficult to prepare by other methods. Wepropose the 1,4-elimination (CF₃SO₂ + H) as the firststep, since it is the less energetic process - corroborated by calculations. Acompetitive reaction (CO₂ extrusion) also occurs, yielding undesiredproducts.