The present invention provides an improved process for producing an alkylated aromatic compound from an at least partially untreated alkylatable aromatic compound having catalyst poisons, wherein said alkylatable aromatic compound stream is treated to reduce catalyst poisons with a treatment composition having a surface area/surface volume ratio of greater than or equal to 30 in−1 (12 cm−1) in a treatment zone separate from an alkylation reaction zone under treatment conditions including a temperature of from about 30° C. to about 300° C. to form an effluent comprising said treated alkylatable aromatic compound.