Preparation of organometallic uracil-analogue Fischer carbene complexes: Comparative study of conventional heating vs microwave irradiation

Mono and disubstituted ureas react with alkynyl Fischer carbene complexes to give mono and di N,N-substituted organometallic uracil analogues. An optimization of the process using different starting metal carbene complexes and variously substituted ureas under conventional heating (with and without solvent) and microwave irradiation techniques is reported. The synthesis of the metal–carbene analog of the commercially available dimethyl uracil is reported.