1-Bromo-3-chloropropane → 3-(3-Chloropropyl)-5-nitrobenzo[d]oxazol-2(3H)-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

5-Nitro-3H-benzoxazol-2-one (5.35 g, 29.7 mmol) in Acetone (300 mL) was treated with Potassium carbonate (6.99 g, 50.6 mmol) then 1-Bromo-3-chloropropane (10.0 mL, 101 mmol) was added. After 45 min, the mixture was heated to 55° C. overnight. The reaction was cooled, diluted with 100 mL water and 150 mL EtOAc. The layers were separated, the org. washed with brine (50 mL), dried over sodium sulfate, filtered through a ½″h×2″w pad of SiO2 and conc. in vacuo. to near dryness. The oily remainder was suspended in 100 mL 5% EtOAc:Hexane, resulting in precipitation of the product. The solids were triturated for 2 h to break up the solids, collected by filtration and washed with hexane (2×60 mL). After drying, 3-(3-Chloro-propyl)-5-nitro-3H-benzoxazol-2-one was isolated as yellow solids (7.52 g, 99%). 1H-NMR (DMSO): 8.27 (d, 1H, J=2.2 Hz), 8.10 (dd, 1H, J=2.2, 8.8 Hz), 7.59 (d, 1H, J=8.8 Hz), 4.04 (t, 2H, J=6.7 Hz), 3.75 (t, 2H, J=6.5 Hz), 2.17 (m, 2H).

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