A reactor, which is capable of accommodating a reaction in which at least three phases are present and at least one gaseous starting material and at least one liquid starting material are reacted in cocurrent over a fixed-bed catalyst to give one or more product(s), contains at least one first zone in which a catalyst is present as a fixed bed; and at least one second zone whose size corresponds to a reactor cross section and which is separated from the at least one first zone by a distributor plate provided with at least one hole and in which at least one liquid and at least one gaseous starting material enter the reactor. The distributor plate is provided with at least one static mixer which is located in the at least one hole on at least one side of the distributor plate.