Sodium Carbonate → 5-(3-Amino-2-methylphenyl)-1-methyl-3-[4-(morpholine-4-carbonyl)-phenylamino]-1H-pyrazin-2-one

Participants

Reaction Conditions

Reaction Steps

A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with 101d (9.23 g, 23.5 mmol), 1,4-dioxane (250 mL) and aqueous 0.71M sodium carbonate (50 mL, 35.5 mmol). After bubbling argon through the resulting solution for 15 minutes, 101f (6.58 g, 28.2 mmol) and tetrakis(triphenylphosphine)palladium (4.06 g, 3.51 mmol) were added and the reaction mixture then heated at 100° C. for 38 h. After this time the reaction was cooled to room temperature and partitioned between water (1 L) and methylene chloride (300 mL). The aqueous phase was separated and re-extracted with methylene chloride (2×300 mL). A white precipitate of the product present in the combined organic extracts was filtered and retained. The organic phase was extracted with 2N hydrochloric acid (2×200 mL) and then discarded. The acidic aqueous phase was made basic with 2N sodium hydroxide to pH 8-10 and extracted with methylene chloride (3×300 mL). The combined organic extracts were dried over sodium sulfate, filtered, then combined with the white precipitate (vide supra) and concentrated under reduced pressure. The resulting white solid was triturated with hot ethanol (100 mL), filtered, and washed with ethanol (2×40 mL). The filter cake was dissolved in chloroform, the solution was concentrated under reduced pressure and dried to a constant weight under high vacuum at 50° C. to afford an 84% yield of 101g (8.31 g) as an off-white solid: mp 274-275° C.; 1H NMR (500 MHz, CDCl3) δ 9.40 (s, 1H), 8.09 (d, 2H, J=8.5 Hz), 7.34 (d, 2H, J=8.5 Hz), 7.14 (s, 1H), 6.93 (t, 1H, J=7.5 Hz), 6.66 (d, 1H, J=7.5 Hz), 6.57 (d, 1H, J=7.5 Hz), 4.92 (bs, 2H), 3.58 (bs, 4H), 3.54 (s, 3H), 3.48 (bs, 4H), 2.09 (s, 3H); MS (ESI+) m/z 420 (M+H).

Provenance & Evidence