Abstract: The yield of 2,5,6-trimethyl-cyclohex-2-en-1-one is increased by reacting diethyl ketyone, in the presence of an alkali, with crotonaldehyde or a compound which is converted to crotonaldehyde under the reaction conditions chose, and working up the reaction mixture by distillation, by a method in which the distillation residue obtained is either(a) heated at from 120.degree. to 250.degree. C. in particular from 120.degree. to 200.degree. C., with the addition of a catalytic amount of an alkali, or(b) heated at from 150.degree. to 250.degree. C. without the addition of such a substance,and the mixture of 2,5,6-trimethylcyclohex-2-en-1-one and diethyl ketone which is formed from the distillation residue as a result of the heat treatment is separated by distillation.

Abstract: A mechanical process for filling the tubes (3) of tubular reactors with granular solids, e.g. catalysts, wherein two or more streams of material, e.g. of different catalytic activity, can be introduced in a controlled manner into each tube (3) which is to be filled, from two or more stock vessels (1,2) via two or more dispensing devices (MI, MZ) mounted above the upper tube end plate (13). By this process, different thermal/catalytic reaction profiles can be achieved over the length of the tube, or in certain groups of tubes within the tubular reactor, with substantially less time being required for filling the tubes (3).