Forecasts of cohort mortality after age 50

A process is disclosed for preparing N,N'-disubstituted urea by reacting an amine and CO/O2 mixture gas in the presence of a catalyst system comprising at least one selenium compound selected from SeO2, (CH3O)Se(O)(OH) and (CH3CH2O)Se(O)(OH), and M2CO3 (M=alkali metal) as a co-catalyst. The process enables less active aromatic amine with a low reactivity as well as an aliphatic amine to be easily transformed into disubstituted urea avoiding the use of expensive precious metal catalysts.