The present disclosure relates to a process for production of a monoalkyl aromatic compound by alkylation of alkylatable aromatic compounds with an alkylating agent in a reactor comprising at least a first and a second series-connected alkylation reaction zones and a cooler disposed between the first and the second series-connected alkylation reaction zones. The process comprising a step of cooling at least a portion of an effluent withdrawn from the first alkylation reaction zone before being introduced into the second alkylation reaction zone.