Isobutyl chloroformate → 1,1-dimethylethyl 7-(2-[(2-fluoroethyl)amino]-1-{[(2-methylpropyl)oxy]carbonyl}-1H-benzimidazol-5-yl)-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

Isobutyl 5-bromo-2-(2-fluoroethylamino)-1H-benzo[d]imidazole-1-carboxylate (55 mg, 0.15 mmol) and (4-{[(1,1-dimethylethyl)oxy]carbonyl}-2,3,4,5-tetrahydro-1,4-benzoxazepin-7-yl)boronic acid (example 1, step 2) (50 mg, 0.17 mmol) were taken into dioxane (1 mL) and water (0.2 mL) followed by addition of dichloro[1,1-bis-(diphenylphosphino]ferrocenepalladium (II) dichloromethane adduct (8.5 mg) and DIPEA (0.11 mL, 0.6 mmol) and the mixture was heated to 85° C. for 12 h. The mixture was then cooled and diluted with ethyl acetate then dried over anhydrous sodium sulfate and filtered through a plug of silica gel with an ethyl acetate wash. The organic solution was then concentrated to an oil. The residue was taken into THF (2 mL) followed by sequential addition of DIPEA (0.05 mL, 0.29 mmol) and isobutyl chloroformate (0.01 mL, 0.08 mmol) then the mixture was stirred for 30 minutes. The mixture was concentrated and the residue purified by silica gel chromatography (1.5:1 hexanes:ethyl acetate) to give 1,1-dimethylethyl 7-(2-[(2-fluoroethyl)amino]-1-{[(2-methylpropyl)oxy]carbonyl}-1H-benzimidazol-5-yl)-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (59.4 mg, 75% yield) as a colorless amorphous residue. MS (EI) for C28H35FN4O5: 528 (MH+).

Provenance & Evidence