||With potassium carbonate; In DMF (N,N-dimethyl-formamide); at 80℃;
||A mixture of <strong>[932-35-4]3-hydroxypyridine-2-carbonitrile</strong> d (10 mmol, 1.2 g), chloroacetone (1 equiv. , 10 mmol, 0.93 g) and potassium carbonate (1 equiv., 10 mmol, 1.38 g) in DMF (30 ml) was heated at 80C overnight. The reaction mixture was poured into ice-water (200 ml) and the precipitate was filtered off and dried to afford intermediate e (1.4 g, yield = 80%, purity (LC) > 95%). To a stirred mixture of intermediate e (7.9 mmol, 1.39 g) and cyanoacetic acid (1 equiv. , 7.9 mmol, 0.675 g) in DMF (20 ml) was added EDCI (1 equiv. , 7.9 mmol, 1.51 g) and the reaction mixture was stirred overnight at room temperature. The mixture was poured into ice-water (150 ml) causing a precipitation. The solid was filtered off and dried by co-evaporation with tetrahydrofuran and then with toluene. The residue was mixed with isopropanol (15 ml) and ethyl-diisopropylamine (1 equiv., 7.9 mmol, 1.02 g) and heated to 80C during 4h. After cooling to room temperature, a solid was filtered off affording intermediate f (1.35 g, yield = 76%, purity (LC) > 95%). A mixture of intermediate f (1.0 mmol, 0.225 g), copper (II) acetate(2 equiv. , 2.0 mmol, 0.363 g), 4-nitrophenylboronic acid (2.0 equiv. , 2.0 mmol, 0.334 g), triethyl- amine (2.0 equiv. , 2.0 mmol, 0.202 g) and pyridine (2.0 equiv. , 2.0 mmol, 0.158 g) in dichloromethane (5 ml) was stirred overnight at room temperature in a reaction vial provided with a calcium chloride tube. The reaction mixture was dilluted with dichloromethane (50 ml), washed with water, dried (MgS04), filtered and evaporated under reduced pressure. The crude compound was purified by chromatography (silica gel, eluent: 2% methanol in dichloromethane) to afford compound 3 (30 mg, yield = 8 %, purity (LC) = 82 %).