Chloroacetic Acid → 2-Chloroacetophenone

Temperature

0 °C

To 5 mL of tetrahydrofuran was added hexamethyldisilazane (6.6 mmol) under the atomosphere of nitrogen gas and after the solution was cooled to 0° C., 6.67 mL of 0.9 M n-butylmagnesium chloride/tetrahydrofuran (6 mmol) was added. The mixture was stirred at 0° C. for 10 minutes. Then, after cooling to -30° C., a solution of 284 mg (3.0 mmol) of monochloroacetic acid and 136 mg (1 mmol) of methyl benzoate in 5 mL of tetrahydrofuran was added dropwise for 5 minutes. This mixture was stirred at -30° C. for 30 minutes and, while the temperature was allowed to rise to room temperature, was further stirred for 1 hour. This reaction mixture was poured in 1N-HCl (50 mL) and extracted with ethyl acetate (50 mL×2). The extract was washed with saturated aqueous NaHCO3 solution (50 mL×1) and water (30 mL×1) in that order and dries over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated to provide a light-yellow oil. Comparative HPLC analysis of this oil with an authentic sample revealed that the oil was predominantly composed of the objective phenacyl chloride (reaction yield 84.3%). Methylbenzoate (reaction yield 17.5%) was obtained as a byproduct.

1. temperatureThen, after cooling to -30° C.
2. stirringThis mixture was stirred at -30° C. for 30 minutes and, while the temperature
3. customto rise to room temperature
4. stirringwas further stirred for 1 hour
5. extractionextracted with ethyl acetate (50 mL×2)
6. washThe extract was washed with saturated aqueous NaHCO3 solution (50 mL×1) and water (30 mL×1) in that order and dries over anhydrous magnesium sulfate
7. filtrationAfter filtration
8. concentrationthe filtrate was concentrated
9. customto provide a light-yellow oil

ORD record

ord-d2fadcda1d344419b697b53eed3942b3

Source dataset

uspto-grants-1999_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05929284