Ammonium Chloride → HCID 2758094, compound

2-(2-Bromoethyl)-1,3-dioxolane (32.7 ml) was added dropwise within 15 minutes under argon and while stirring at a maximum 30° C. to a suspension of Rieke magnesium, prepared from 37.5 g of magnesium chloride, in 1200 ml of absolute tetrahydrofuran. The suspension was stirred at room temperature for 15 minutes, cooled to 0° C. and, after the addition of 36.4 g of copper(I) bromide, stirred at 0° C. for 15 minutes. After cooling to -70° C. 45.0 g of 3,4-dichlorobenzoyl chloride dissolved in 100 ml of absolute tetrahydrofuran were added dropwise within 20 minutes. The reaction mixture was stirred at -70° C. for 30 minutes and at room temperature for 2 hours and subsequently hydrolyzed with 800 ml of saturated ammonium chloride solution while cooling at a maximum 20° C. After the addition of 500 ml of water the mixture was extracted three times with ethyl acetate (1×800 ml, 2×500 ml). The combined organic extracts were dried over MgSO4 and freed from solvent. The residue, 65.0 g of brown oil, was chromatographed on 1500 g of silica gel with ethyl acetate/hexane (1:3) as the eluent. 30.4 g (51%) of 3',4'-dichloro-3-(1,3-dioxolan-2-yl)propiophenone were isolated as a yellow-orange oil.

1. temperaturecooled to 0° C.
2. stirringstirred at 0° C. for 15 minutes
3. temperatureAfter cooling to -70° C
4. additionwere added dropwise within 20 minutes
5. temperaturewhile cooling at a maximum 20° C
6. extractionwas extracted three times with ethyl acetate (1×800 ml, 2×500 ml)
7. dry with materialThe combined organic extracts were dried over MgSO4
8. customThe residue, 65.0 g of brown oil, was chromatographed on 1500 g of silica gel with ethyl acetate/hexane (1:3) as the eluent

ORD record

ord-25f4e8a01b5f4de092c78bd46915fc79

Source dataset

uspto-grants-1994_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05292732