Phosgene-free synthesis of 1,3-diphenylurea via catalyzed reductive carbonylation of nitrobenzene

1,3-Diphenylurea (DPU) has been proposed as a synthetic intermediate for phosgene-free synthesis of methyl N-phenylcarbamate and phenyl isocyanate, which are easily obtained from the urea by reaction with methanol. Such an alternative route to synthesis of carbamates and isocyanates necessitates an improved phosgene-free synthesis of the corresponding urea. In this work, it is reported that Pd(II)-diphosphine catalyzed reductive carbonylation of nitrobenzene in acetic acid (AcOH)-methanol proceeds in high yield and selectivity as a one-step synthesis of DPU. We have found that the catalytic activity and selectivity of this process depends on solvent composition and on the bite angle of the diphosphine ligands. Under optimum reaction conditions, yields in excess of 90 molar % and near-quantitative selectivity can be achieved

Suivi médical et biologique de 100 patients diabétiques de type 2 (étude rétrospective afin d'optimiser les règles de prise en charge des patients)

BORDEAUX2-BU Santé (330632101) / SudocSudocFranceF

SYNTHESE DE CHLOROCARBAMATES POUR LA FORMATION D'AMIDES PAR COUPLAGE AVEC DES ORGANOMETALLIQUES. APPLICATIONS EN CHIMIE DU CARBONE-11

CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Etude de la synthèse d'amides par couplage de chlorocarbamates et d'organométalliques en vue de son application en chimie du carbone-11

CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF