Triethylamine → 8-Bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulen-2-ylamine

Participants

Reaction Conditions

Reaction Steps

To a solution of 8-bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulene-2-carboxylic acid (12.5 g, 38.3 mmol) in tert-butanol (250 mL) were added triethylamine (5.5 mL, 40 mmol) and diphenylphosphoryl-azide (8.6 mL, 40 mmol). The reaction mixture was stirred at 95° C. for 16 hours, then allowed to cool down to RT, and concentrated in vacuo. The resultant residue was dissolved in EtOAc, washed successively with water, aqueous saturated sodium bicarbonate solution followed by brine, dried (MgSO4) and concentrated in vacuo. The resultant residue was dissolved in DCM (150 mL) and treated with TFA (50 mL). The reaction mixture was stirred at RT for 3 hours then concentrated in vacuo. The resulting residue was triturated with 20% EtOAc/cyclohexane and filtered to afford 8-Bromo-4,5-dihydro-6-oxa-3-thia-1-aza-benzo[e]azulen-2-ylamine as an off-white solid (7.94 g, 70%). LCMS: RT=3.13 min, [M+H]+=297/299

Provenance & Evidence