Formanilide and carbanilide from aniline and carbon dioxide

Earlier syntheses of formamides from the catalytic hydrogenation of CO(2) 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 CO(2), H(2) and aniline with the use of 1,8-diazabicyclo[5.4.0]undec-7-ene. Omission of the H, reductant causes the selectivity to switch to the production of carbanilide (1,3-diphenylurea). (C) 2003 Elsevier Science Ltd. All rights reserved.