Benzeneselenol is prepared by the reaction of phenylmagnesium bromide and selenium:
:PhMgBr + Se → PhSeMgBr
:PhSeMgBr + HCl → PhSeH + MgBrCl
Since benzeneselenol does not have a long shelf life, it is often generated in situ. A common method is by reduction of diphenyldiselenide. A further reason for this conversion is that often, it is the anion that is sought.