21243-09-4 → 8-fluoro-2,3-dihydro-4H-thiochromen-4-one

Temperature

2.5 °C

3-[(2-Fluorophenyl)sulfanyl]propanoic acid (4.0 g, 20 mmol) was mixed with concentrated sulphuric acid (20 ml) at 0–5° C. The reaction solution was stirred at 0 to 5° C. for 3 h then allowed to warm up to room temperature overnight. The mixture was quenched dropwise into ice to give a white suspension. The aqueous phase was extracted with ethyl acetate (1×200 ml, 1×100 ml). The combined organic phases were washed with saturated sodium bicarbonate solution (1×50 ml), water (1×50 ml), 1M hydrochloric acid (50 ml) and water (2×50 ml). The organic phase was dried over magnesium sulphate, filtered and concentrated under vacuum. The title compound was isolated as a yellow solid (2.10 g, 11.5 mmol, 58%).

1. temperatureto warm up to room temperature overnight
2. customThe mixture was quenched dropwise into ice
3. customto give a white suspension
4. extractionThe aqueous phase was extracted with ethyl acetate (1×200 ml, 1×100 ml)
5. washThe combined organic phases were washed with saturated sodium bicarbonate solution (1×50 ml), water (1×50 ml), 1M hydrochloric acid (50 ml) and water (2×50 ml)
6. dry with materialThe organic phase was dried over magnesium sulphate
7. filtrationfiltered
8. concentrationconcentrated under vacuum

ORD record

ord-a0ed496bc0d24e5ea9c582b5cb459602

Source dataset

uspto-grants-2006_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07081456B2