1: 35 percent / toluene / 2 h / 110 °C 2: 95 percent / NEt3 / dimethylformamide / 4 h 3: 76 percent / Na2CO3 / PdCl2(dppf) / dimethylformamide; H2O / 1 h / 100 °C 4: 63 percent / 1,3-dimethylbarbituric acid / Pd(PPh3)4 / tetrahydrofuran / 12 h / 65 °C View Scheme