MECHANOHYDROGENATION

Treatment of naphthalene and biphenyl with alumina and hydrogen in a v ibratory mill for about 5h at ambient temperature gives up to 75 % and 15 % of tetralin and phenylcyclohexane respectively. This suggests th at the previously reported(1) disproportionation of naphthalene and bi phenyl to give tetralin and phenylcyclohexane by analogous treatment u nder nitrogen proceeds at least partially by a step involving molecula r hydrogen. However, these observations are not general because identi cal mechanical treatment of trans-stilbene under hydrogen gave less bi benzyl than under nitrogen. (C) 1997 Elsevier Science Ltd. All rights reserved.