Phosphorus trichloride → 6-Chloro-1-benzothiophen-3(2H)-one

Temperature

100 °C

To a solution of m-chlorothiophenoxyacetic acid (5.00 g, 24.7 mmol) in chlorobenzene (25 ml) was added phosphorous trichloride (2.90 ml) at room temperature, and the reaction was allowed to proceed with vigorous stirring at 100° C. for 2 hours. After cooling to room temperature, anhydrous aluminum chloride (3.70 g, 27.7 mmol) was added thereto, and the reaction was allowed to proceed at room temperature for 30 minutes, followed by stirring at 100° C. for 1.5 hours. After cooling to room temperature, the reaction mixture was poured into ice-water and separated with a separatory funnel. The aqueous layer was extracted with toluene (150 ml×2). The combined organic layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting residue was subjected to chromatography on silica gel to give 6-chloro-2,3-dihydro-benzothiofuran-3-one (2.83 g, 15.3 mmol; yield, 62%), m.p., 123.8° C.

1. temperatureAfter cooling to room temperature
2. waitto proceed at room temperature for 30 minutes
3. stirringby stirring at 100° C. for 1.5 hours
4. temperatureAfter cooling to room temperature
5. customseparated with a separatory funnel
6. extractionThe aqueous layer was extracted with toluene (150 ml×2)
7. dry with materialThe combined organic layer was dried over anhydrous magnesium sulfate
8. concentrationconcentrated under reduced pressure

ORD record

ord-f4ca93802fce4498af0973c405e23539

Source dataset

uspto-grants-1995_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05451607