Synthesis of p38 MAP kinase inhibitor BIRB 796 and analogs via copper-mediated N-arylation reaction

Direct N-arylation of urea (5) with various arylboronic acids mediated by cupric acetate furnished BIRB796 and a range of N-substituted BIRB796 analogs in good to moderate yields in one step. Urea (5) was readily synthesized from commercially available compounds.