The present disclosure provides a process for selectively producing a desired monoalkylated aromatic compound comprising the step of contacting in a reaction zone an alkylatable aromatic compound with an alkylating agent in the presence of catalyst comprising a porous crystalline material under at least partial liquid phase conditions, said catalyst manufactured from extrudate to comprise catalytic particulate material of from about 125 microns to about 790 microns in size, having an Effectiveness Factor increased from about 25% to about 750% from that of the original extrudate, and having an external surface area to volume ratio of greater than about 79 cm−1.