Acetyl chloride, 2-(2-chlorophenyl)- → 8-Chloro-1,2,3,4-tetrahydronaphthalen-2-one

Temperature

-78 °C

AlCl3 (46.5 g; 0.348 mol) was slurried in 400 ml of methylene chloride. The mixture then was cooled to -78° C., and a solution of 32.76 g (0.174 mol) of the previously produced o-chlorophenylacetyl chloride in 100 ml of methylene chloride was added dropwise over 1 hour. The dry ice/acetone bath then was replaced with an ice water bath. Ethylene was bubbled into the reaction mixture during which time the temperature rose to 15° C. The ethylene addition was discontinued, and the mixture was allowed to stir at about 5° C. for 4 hours. Ice then was added to the mixture to decompose any remaining aluminum complexes. Upon termination of the exotherm, the mixture was diluted with water (500 ml) and stirred vigorously until all of the solid was dissolved. The aqueous and organic phases were separated, and the organic phase was washed 3 times with 400 ml each of 1N HCl and twice with 400 ml each of 10% aqueous sodium bicarbonate. The organic phase then was dried over sodium sulfate and evaporated in vacuo to obtain a pale orange residue. The residue was dissolved in a 1:1 mixture of hexane and ether and applied to a flash silica column which was then eluted with a 1:1 mixture of hexane and ether to give a light yellow residue which was crystallized from a 4:1 mixture of hexane and ether to obtain 10.55 g (33.6%) of the title compound.

1. customEthylene was bubbled into the reaction mixture during which time the temperature
2. customrose to 15° C
3. additionThe ethylene addition
4. additionIce then was added to the mixture
5. additionUpon termination of the exotherm, the mixture was diluted with water (500 ml)
6. stirringstirred vigorously until all of the solid
7. dissolutionwas dissolved
8. customThe aqueous and organic phases were separated
9. washthe organic phase was washed 3 times with 400 ml each of 1N HCl
10. dry with materialThe organic phase then was dried over sodium sulfate
11. customevaporated in vacuo
12. customto obtain a pale orange residue
13. washwas then eluted with a 1:1 mixture of hexane and ether
14. customto give a light yellow residue which
15. customwas crystallized from a 4:1 mixture of hexane and ether

ORD record

ord-4c7efcf364e4455987b585fcfbbd3500

Source dataset

uspto-grants-1991_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05026707