9-Bromo-2,3-diiodo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene → 10-Bromo-2-iodo-5,6-dihydrobenzo[F]imidazo[1,2-D][1,4]oxazepine

Participants

Reaction Conditions

Reaction Steps

Into a 20 L 4-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen was placed a solution of 9-Bromo-2,3-diiodo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene (900 g, 1.74 mol, 1.00 equiv) in tetrahydrofuran (9 L), followed by the addition of EtMgBr (755 mL, 1.30 equiv) dropwise with stirring at −30° C. over 60 min. The resulting solution was stirred at −30-15° C. for 10 min, quenched by the addition of 1500 mL of saturated aqueous NH4Cl and extracted with 3×3000 mL of tetrahydrofuran. The combined organic layers were washed with 2×2000 mL of brine, dried over anhydrous sodium sulfate and concentrated under vacuum to afford 450 g (66%) of 9-Bromo-2-iodo-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene as a yellow solid.

Provenance & Evidence