Triethylamine → [2-Methyl-4-(2-methyl-4,5-dihydro-1-oxa-3,6-diaza-benzo[e]azulene-6-carbonyl)-benzyl]-carbamic Acid Tert-butyl Ester

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Reaction Steps

A solution of 4-(tert-butoxycarbonylamino-methyl)-3-methyl-benzoic acid from Example E2h (400 mg, 1.5 mmol) in dichloromethane (20 ml) and triethylamine (to pH9) was treated with WSCD (573 mg, 3.0 mmol) and DMAP (183 mg, 1.5 mmol). The solution was stirred for 30 min at room temperature then 2-methyl-5,6-dihydro-4H-1-oxa-3,6-diaza-benzo[e]azulene from Example E6 (300 mg, 1.5 mmol) was added and the mixture was heated at reflux for 3 days. WSCD (287 mg, 1.5 mmol) was added and the mixture was heated at reflux for another 24h then concentrated in vacuo. The residue was dissolved in EtOAc, washed with 1N KHSO4, water then brine, dried and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (eluant; EtOAc) to yield the title compound (62 mg, 9%).

Provenance & Evidence