A reactor for carrying out catalyzed liquid reactions in which the catalyst is present as a dispersion in the reaction zone. The reactor includes at least one inlet and outlet, with all starting materials being fed in via the inlet and all products being discharged via the outlet. The inlet and outlet can be switched so that an exit previously serving as the outlet is utilized as an entrance serving as the inlet and at the same time an entrance previously serving as the inlet is utilized as an exit serving as the outlet. The inlet and outlet each include a filter element that keeps the catalyst in the reactor. The reactor also includes a device that ensures homogeneous distribution of the catalyst and the starting materials in the reactor. This reactor can carry out reactions at a high solids content without the catalyst having to be separated off from a product stream in an extra process step and without regular cleaning and thus shutdown of the process being necessary.