N-methyl-2-pyrrolidone → 1-(((5S,7S)-3-(6-methoxypyridin-3-yl)-7-methyl-2-oxo-1-oxa-3-azaspiro[4.5]decan-7-yl)methyl)-1H-benzo[d]imidazole-6-carbonitrile

Participants

Reaction Steps

To a solution of tert-butyl (6-methoxypyridin-3-yl)carbamate (5.98 g, 26.7 mmol) in tetrahydrofuran (THF) (20 mL) at −78° C. under N2 was added n-BuLi (2.5M in hexanes) (10.66 mL, 26.7 mmol). The mixture was allowed to warm up to RT and stirred for 20 min, to the mixture was added 1-{[(3S,5S)-5-methyl-1-oxaspiro[2.5]oct-5-yl]methyl}-1H-benzimidazole-6-carbonitrile (6.0 g, 21.33 mmol) followed by N-methyl-2-pyrrolidone (NMP) (20.00 mL). The mixture was heated at 75° C. for 2 days and then cooled to RT. The reaction mixture was diluted with EtOAc/H2O and extracted with 3×EtOAc. The organic layers were washed with 2× brine, dried over Na2SO4, filtered and concentrated. To the residue was added 250 mL of i-PrOH, heated to reflux for 2 hours, and then cooled to RT for 2 days. The solid was filtered and air dried to afford 1-(((5S,7S)-3-(6-methoxypyridin-3-yl)-7-methyl-2-oxo-1-oxa-3-azaspiro[4.5]decan-7-yl)methyl)-1H-benzo[d]imidazole-6-carbonitrile as a white solid (7.43 g, 79% yield).

Provenance & Evidence