A process for producing a monoalkylated aromatic compound in an alkylation reaction zone, comprising providing upstream of said alkylation reaction zone a reactive guard bed having a catalyst of *BEA, MWW, or FAU framework structure and an alkylation feed wherein at least a portion of any reactive impurities are removed from the alkylation feed to form an effluent; and providing the effluent and a first catalytic particulate material which comprises MCM-56 and an alumina binder sized 50-60 mesh and having a ratio of surface area over volume ratio in the range of 241 to 2867 cm-1 and optionally additional alkylating agent to said alkylation reaction zone; and contacting said alkylatable aromatic compound and said alkylating agent with said catalytic particulate material in said alkylation reaction zone maintained under alkylation conditions, to form a product comprised of said monoalkylated aromatic compound.