Catalytic hydrogenation of benzothiophene to 2,3-dihydrobenzothiophene

Hydrogenation of benzothiophene in a solution of cyclohexane in the presence of palladium sulfide catalyst at 5 MPa and 433–473 K has been studied. The rate of the formation of 2,3-dihydrobenzothiophene is described by a first-order equation. The apparent activation energy is 58±4 kJ/mol. For attaining 100% selectivity to 2,3-dihydrothiophene, the total conversion of benzothiophene should be below 60%.