Potassium Carbonate → tert-Butyl {5-[(3-chloro-2,5-dioxo-4-phenyl-2,5-dihydro-1H-pyrrol-1-yl)methyl]pyridin-2-yl}carbamate

3-Chloro-4-phenyl-1H-pyrrole-2,5-dione (1.55 g, 7.47 mmol) was dissolved in DMF (25 mL) under nitrogen atmosphere and cooled in an ice-bath. tert-Butyl [5-(bromomethyl)pyridin-2-yl]carbamate (2.14 g, 7.46 mmol) was added followed by anhydrous potassium carbonate (1.03 g, 7.47 mmol)and the mixture was stirred for one and a half hours whereafter the cooling-bath was removed. The mixture was stirred for another two hours and then neutralized with 1% HCl. Water (100 mL) was added and the mixture was extracted with CH2Cl2 (50 mL×3). The extracts were combined, washed with water (100 mL×2), dried with magnesium sulphate, filtered and evaporated. The crude product (3.41 g) was used without further purification. 1H NMR (400 MHz, CDCl3): δ 8.32 (d, J=2 Hz, 1H), 7.92-7.89 (m, 3H), 7.83 (bs, 1H), 7.72 (dd, J=9, 2 Hz, 1H), 7.49-7.47 (m, 3H), 4.71 (s, 2H), 1.52 (s, 9H).