Phosphorus oxychloride → 2-Chloro-4-(3-trifluoromethyl-phenyl)-thiazole

A mixture of 24.55 g (100.1 mmole) of 4-(3-trifluoromethyl-phenyl)-3H-thiazol-2-one and 75 mL (0.811 mole) of phosphorus oxychloride was heated at reflux for 3 hours. The cooled mixture was concentrated under reduced pressure. The residue was diluted with ethyl acetate and poured onto ice. The mixture was made basic by the addition of saturated sodium carbonate solution. The ethyl acetate layer was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel chromatography, eluting with ethyl acetate-hexanes (gradient 10:90-20:80) to give 17.09 g of 2-chloro-4-(3-trifluoromethyl-phenyl)-thiazole as a light brown solid.

1. temperaturewas heated
2. temperatureat reflux for 3 hours
3. concentrationThe cooled mixture was concentrated under reduced pressure
4. additionThe residue was diluted with ethyl acetate
5. additionpoured onto ice
6. additionThe mixture was made basic by the addition of saturated sodium carbonate solution
7. dry with materialThe ethyl acetate layer was dried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by silica gel chromatography
11. washeluting with ethyl acetate-hexanes (gradient 10:90-20:80)

ORD record

ord-407d0c95560848a88b584feee77a1a98

Source dataset

uspto-grants-2011_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08044213B2