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 h, then allowed to cool down to RT, and concentrated in vacuo. The resultant residue was dissolved in ethyl acetate, washed successively with water, aqueous saturated sodium bicarbonate solution and brine, dried (MgSO4) and concentrated in vacuo. The resultant residue was dissolved in DCM (150 mL) and treated with trifluoroacetic acid (50 mL). The reaction mixture was stirred at RT for 3 h then concentrated in vacuo. The resulting residue was triturated with 20% ethyl acetate/cyclohexane and filtered to afford the title compound as an off-white solid (7.94 g, 70%). LCMS (Method A): RT=3.13 min, [M+H]+=297 and 299. 1H NMR (DMSO-d6): 8.01 (1 H, d, J=8.6 Hz), 7.30-7.25 (1 H, d, J=8.6, 2.1 Hz), 7.19 (1 H, d, J=2.1 Hz), 4.27 (2 H, t, J=5.1 Hz), 3.08 (2 H, t, J=5.1 Hz).

Provenance & Evidence