Dimethyl Sulfoxide → 4-(6-tert-Butyl-8-fluoro-1-oxo-1H-phthalazin-2-yl)-2-chloro-pyridine-3-carbaldehyde

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Reaction Conditions

Reaction Steps

In a 50 mL round-bottomed flask, 2-chloro-4-iodonicotinaldehyde (389 mg, 1.45 mmol, Eq: 1.6), 6-tert-butyl-8-fluorophthalazin-1(2H)-one (200 mg, 908 μmol, Eq: 1.00) and potassium carbonate (251 mg, 1.82 mmol, Eq: 2) were combined with DMSO (8 ml) to give a yellow solution. The solution was degassed for 5 min with argon. Copper(I) iodide (173 mg, 908 μmol, Eq: 1.00) was added. The reaction mixture was heated to 110° C. and stirred for 2 h and the reaction was allowed to cool to room temperature. The reaction was diluted with 1:1 H2O/sat. NH4Cl (80 mL) and the resulting solid collected by filtration. The solid was washed several times with 1:1 H2O/sat. NH4Cl, then water (2×) and then EtOAc:hexanes (3:1, 2×). A lot of color in the organic phase. A brown solid remained. Solid was washed with EtOAc and then CH2Cl2 several times. The combined organic extracts were washed with water, dried over MgSO4 and concentrated in vacuo. The resulting residue was purified by flash chromatography (silica gel, 40 g, 5% to 30% EtOAc in hexanes) to afford the desired product (170 mg) as a white solid. (M+H)+=360 m/e. 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 1.42 (s, 9 H) 7.40-7.65 (m, 3 H) 8.24 (d, J=2.64 Hz, 1 H) 8.66 (d, J=5.29 Hz, 1 H) 10.32 (s, 1 H).

Provenance & Evidence