O-Phenylenediamine → Benzyl (1S)-2-[(2-aminophenyl)amino]-1-[3-bromo-4-(1,1-dioxido-3-oxoisothiazolidin-5-yl)benzyl]-2-oxoethylcarbamate

Participants

Reaction Steps

(2S)-2-[(Benzyloxy)-carbonyl]amino-3-[3-bromo-4-(1,1-dioxido-3-oxoisothiazolidin-5-yl)phenyl]propanoic acid (65.3 mg, 0.128 mmol) in DMF (4 mL) was treated with benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (67.8 mg, 0.153 mmol). After 5 minutes 1,2-benzenediamine (20.7 mg, 0.192 mmol) and N,N-diisopropylethylamine (111 μL, 0.638 mmol) were added and the solution stirred at rt for 2 h. Purification by preparative LCMS afforded product as a white solid (58 mg, 76%). 1H NMR (400 MHz, CD3OD): δ 7.72 (s, 1H), 7.56–7.23 (m, 10H), 6.91–6.85 (m, 1H), 5.67 (t, J=7.7 Hz, 1H), 5.09 (s, 2H), 4.50–4.47 (m, 1H), 3.46 (dd, J=16.5, 8.8 Hz, 1H), 3.34–3.24 (m, 1H), 3.26–3.08 (m, 2H); LCMS found for C26H26BrN4O6S (M+H)+: m/z=601.

Provenance & Evidence