Formanilide and carbanilide from aniline and carbon dioxide

Earlier syntheses of formamides from the catalytic hydrogenation of CO₂ in the presence of amines were only successful for the preparation of dialkylformamides. After an analysis of the reason for the failure of the reaction using aniline as a starting material, formanilide has been prepared, for the first time, from CO₂, H₂ and aniline with the use of 1,8-diazabicyclo[5.4.0]undec-7-ene. Omission of the H₂ reductant causes the selectivity to switch to the production of carbanilide (1,3-diphenylurea).