1-isopropyl-3-methyl-1H-1,2,4-triazole → 10-bromo-2-(1-isopropyl-3-methyl-1H-1,2,4-triazol-5-yl)-5,6-dihydrobenzo[f]imidazo[1,2-d][1,4]oxazepine

Participants

Reaction Conditions

Reaction Steps

A solution of 1-isopropyl-3-methyl-1H-[1,2,4]triazole (in a 6:4 mixture with 1-isopropyl-5-methyl-1H-[1,2,4]triazole, 0.75 g, 3.6 mmol) in THF (10 mL) was cooled to −25° C. and treated with n-butyllithium (2.5M in hexanes, 1.45 mL, 3.63 mmol) over 5 min under a nitrogen atmosphere and then stirred at this temperature for 1 h. The mixture was then cooled to −30° C. and a solution of zinc chloride (0.5M in THF, 4.22 mL, 2.11 mmol) was added over 5 min. The reaction mixture was stirred between −20° C. and −25° C. for 30 min, then slowly warmed to RT and stirred at this temperature for 30 min. A solution of 9-bromo-2-iodo-4,5-dihydro-6-oxa-1,3a-diazabenzo[e]azulene (1.0 g, 2.557 mmol) in THF (2 mL) was then added followed by Pd(PPh3)4 (148 mg, 0.128 mmol) and the reaction mixture was stirred at 60° C. under a nitrogen atmosphere for 18 h. After cooling to RT, volatiles were removed under reduced pressure and the residue was partitioned between EtOAc and water. The aqueous layer was further washed with EtOAc and the combined organic phases were washed with water, followed by brine, then dried (Na2SO4) and concentrated in vacuo. The resulting residue was purified by column chromatography (Si-PCC, gradient 2-10% MeOH in DCM followed by Si-PCC, eluent 100% methyl acetate) affording the title compound as a white solid (214 mg, 22%). LCMS: RT 3.50 min [M+H]+ 387.8/389.9.

Provenance & Evidence