Formaldehyde → 5-Bromo-1-methyl-3-(5-(1-methylazetidin-3-yloxy)pyridin-2-ylamino)pyridin-2(1H)-one

Participants

Reaction Steps

A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer was purged with nitrogen and charged with 251d (1.10 g, 2.95 mmol), 37% solution of formaldehyde in water (111 mg, 3.70 mmol) and methanol (15 mL). A suspension of sodium cyanoborohydride (540 mg, 8.60 mmol) and zinc chloride (600 mg, 4.40 mmol) in methanol (10 mL) was added, and the reaction was stirred at room temperature for 4 h. After this time, the reaction mixture was concentrated, and the residue was partitioned between 90:10 methylene chloride/methanol (250 mL) and 10% aqueous potassium carbonate (100 mL). The aqueous layer was extracted with 90:10 methylene chloride/methanol (3×150 mL). The combined organic extracts were dried over sodium sulfate, filtered and concentrated under reduced pressure. The resulting residue was purified by column chromatography (silica, 0% to 50% methanol/methylene chloride) to afford a 80% yield (830 mg) of 251e as an brown solid: mp 100-101° C.; 1H NMR (500 MHz, DMSO-d6) d 8.66 (s, 1H), 8.55 (d, 1H, J=2.5 Hz), 7.86 (d, 1H, J=3.0 Hz), 7.47 (d, 1 h, J=2.5 Hz), 7.31 (d, 1H, J=9.0 Hz), 7.24 (dd, 1H, J=9.5, 3.5 Hz), 4.76 (m, 1H), 3.77 (t, 2H, J=7.5 Hz), 3.50 (s, 3H), 3.03 (t, 2H, J=7.5 Hz), 2.26 (s, 3H); MS (ESI+) m/z 366.0 (M+H).

Provenance & Evidence