2-Bromopyridine → 1-[3-(6-tert-Butyl-1-oxo-1H-phthalazin-2-yl)-2-hydroxymethyl-phenyl]-3-(pyridin-2-ylamino)-1H-pyrazole-4-carbonitrile

Participants

Reaction Steps

To a 5 mL microwave reaction vial were introduced 3-amino-1-(3-(6-tert-butyl-1-oxophthalazin-2(1H)-yl)-2-(hydroxymethyl)phenyl)-1H-pyrazole-4-carbonitrile (25 mg, 0.060 mmol), 2-bromopyridine (11 mg, 0.072 mmol), Pd2(dba)3 (3.9 mg, 0.004 mmol), 2-(DICYCLOHEXYLPHOSPHINO)-3,6-DIMETHOXY-2′-4′-6′-TRI-I-PROPYL-1,1′-BIPHENYL (Brett-Phos) (4.5 mg, 0.008 mmol), cesium carbonate (29.5 mg, 0.091 mmol) and suspended in t-butanol (0.609 mL). The reaction vessel was inerted three times by alternating vacuum and an Ar purge, then stirred at room temperature for 5 minutes to give a heterogeneous mixture that turned color from purplish-red to reddish-orange. The reaction was heat to 100° C. (external), during which the color of the reaction mixture changed to orange after ˜2 minutes of heating. After 2 hr, the reaction was judged complete by TLC. The mixture was diluted with EtOAc, filtered through a pad of diatomaceous earth and bound to silica gel. The crude product was purified over silica gel using a 12 g RediSep silica gel cartridge eluting the column with a 30%-100% EtOAc/hexanes gradient to give 1-[3-(6-tert-Butyl-1-oxo-1H-phthalazin-2-yl)-2-hydroxymethyl-phenyl]-3-(pyridin-2-ylamino)-1H-pyrazole-4-carbonitrile (15 mg, 51%) as a white powder.

Provenance & Evidence