Reaction #452431

Reaction equation

diethyl ether

AlCl3

o-chlorophenylacetyl chloride

dry ice acetone

→

title compound

8-chloro-2-tetralone

Solvents

dichloromethane

dichloromethane

hexane

Conditions

Workup

1. 1
   Otherethylene was bubbled into the reaction mixture during which time the temperature
2. 2
   Otherrose to 15° C
3. 3
   workup.ADDITIONThe ethylene addition
4. 4
   workup.ADDITIONIce was then added to the reaction mixture
5. 5
   Otherto destroy aluminum complexes
6. 6
   workup.ADDITIONUpon termination of the exotherm, the reaction mixture was diluted with 500 mL of water
7. 7
   workup.STIRRINGstirred vigorously until all solids
8. 8
   workup.DISSOLUTIONhad dissolved
9. 9
   OtherThe phases were separated
10. 10
    Washthe organic phase was washed with 3×400 mL 1N hydrochloric acid and 2×400 mL saturated aqueous sodium bicarbonate
11. 11
    DryingThe remaining organic phase was then dried over sodium sulfate
12. 12
    Concentrationconcentrated in vacuo
13. 13
    Otherto give a pale orange residue
14. 14
    Washwas then eluted with 1:1 hexane
15. 15
    Otherdiethyl ether to give a light yellow residue which
16. 16
    Otherwas crystallized from 4:1 hexane

Procedure

To a slurry of 46.5 gm (0.348 mole) AlCl3 in 400 mL dichloromethane at -78° C. was added a solution of 32.76 gm (0.174 mole) of the previously prepared o-chlorophenylacetyl chloride in 100 mL dichloromethane dropwise over 1 hour. The dry ice/acetone bath then was replaced with an ice/water bath and ethylene was bubbled into the reaction mixture during which time the temperature rose to 15° C. The ethylene addition was discontinued at the end of the exotherm and the reaction mixture was stirred at about 5° C. for 4 hours. Ice was then added to the reaction mixture to destroy aluminum complexes. Upon termination of the exotherm, the reaction mixture was diluted with 500 mL of water and stirred vigorously until all solids had dissolved. The phases were separated and the organic phase was washed with 3×400 mL 1N hydrochloric acid and 2×400 mL saturated aqueous sodium bicarbonate. The remaining organic phase was then dried over sodium sulfate and concentrated in vacuo to give a pale orange residue. The residue was dissolved in 1:1 hexane:diethyl ether and was poured over a flash silica column which was then eluted with 1:1 hexane:diethyl ether to give a light yellow residue which was crystallized from 4:1 hexane:diethyl ether to give 10.55 gm of the title compound.

Source