Hexachloroethane → 2-Chloro-5-phenyloxazole

Temperature

-78 °C

To a round bottom flask was added 5-phenyloxazole (1.0 gm, 6.89 mmol) and THF (10 mL). The reaction was cooled to −78° C. Then 2.5 M nBuLi (3.03 mL, 7.58 mmol) was added to the reaction at −78° C. The reaction turned to deep red color. After 15 min, hexachloroethane (1.170 mL, 10.33 mmol) was added at −78° C. The reaction was slowly warmed to rt over 2 hrs and then was poured onto ice. The resulting solution was extracted with EtOAc (2×30 ml). The combined EtOAc layers were washed with saturated aqueous NaCl, dried over MgSO4, filtered and concentrated. The resulting residue was purified using silica gel chromatography (ISCO system) eluting with a gradient of 0-100% EtOAc/Hex to give the product, 2-chloro-5-phenyloxazole, (600 mg, 3.34 mmol, 49% yield) as a light pale liquid. Anal. Calcd. for C9H6ClNO m/z 179.1, found: 180.1 (M+H)+; 1H NMR (500 MHz, CDCl3) δ ppm 7.60 (d, J=7.15 Hz, 2H), 7.43 (t, J=7.42 Hz, 2H), 7.38-7.33 (m, 1H), 7.29 (s, 1H); 13C NMR (126 MHz, CDCl3) δ ppm 153.78, 146.16, 129.01, 126.93, 124.03, 123.31.

1. temperatureThe reaction was slowly warmed to rt over 2 hrs
2. additionwas poured onto ice
3. extractionThe resulting solution was extracted with EtOAc (2×30 ml)
4. washThe combined EtOAc layers were washed with saturated aqueous NaCl
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe resulting residue was purified
9. washeluting with a gradient of 0-100% EtOAc/Hex

ORD record

ord-5860fc5cc7584aa6affc32349dfbb410

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08815909B2