No abstract

We have undertaken the preparation of thiophene-l-dioxides in order to study the attack of free radicals on a vinyl sulfone group (-CH= CH-SOz-) contained in a ring. We are also interested in the reactivity of these thiophene-ldioxides as dienes in the Diels-Alder reaction. This paper will describe the condensation of ethyl oxalate with arylmethyl sulfones (R = 0-naphthyl, phenyl, p-chlorophenyl) to give 2,5-diaryl-3,4 -dihydroxythiophene -1 -dioxides (I). The method is outlined below. Na+OET@ R-CHa-SOz--CH~-R

The work reported was carried out to evaluate the limits of utility of commercial pour point depressants and viscosity index improvers with mineral oils, to determine the essential structural features of a pour point depressant, and to extend lresent knowledge of the mechanism of pour point depression.The thixotroly exhibited by Pennsylvania 150 Neutral oil below its pour point, studied with rotational concentric cylinder viscometers, was resolved into two processes occurring simultaneously; a degeneration of the rigid structure, predominantly observed at low rates of shear and occurring very rapidly at high rates of shear and a reversible apparent thixotropy occurring at high rates of shear that is largely attributable to frictional heating effects.