Reaction #1880959

Reaction equation

hydrochloric acid

5,6-dimethoxy-3-methylindan-1-one

hydrochloric acid

→

5,6-dimethoxy-1-methylindane

Yield 75.0%

Solvents

water

water

toluene

Conditions

Workup

1. 1
   OtherThe supernatant was decanted off
2. 2
   workup.ADDITIONto the residue were added, with ice cooling, 42 ml of water
3. 3
   workup.ADDITIONwere added
4. 4
   Temperaturethe mixture was refluxed for 3 days (d)
5. 5
   workup.WAITin the course of which, after 48 h
6. 6
   TemperatureAfter cooling
7. 7
   Extractionthe product was extracted twice in 300 ml of ether
8. 8
   WashThe combined extracts were washed with 100 ml of water and 25 ml of saturated sodium chloride solution
9. 9
   Dryingdried over sodium sulfate
10. 10
    Concentrationconcentrated on a rotary evaporator

Procedure

To a suspension of 53.3 g (815 mmol) of zinc dust in 74 ml of water were added 4 ml of concentrated hydrochloric acid. The supernatant was decanted off after stirring for 30 min, and to the residue were added, with ice cooling, 42 ml of water and then, dropwise, 55 ml of concentrated hydrochloric acid. 28.0 g (136 mmol) of 5,6-dimethoxy-3-methylindan-1-one dissolved in 53 ml of toluene were added and the mixture was refluxed for 3 days (d), in the course of which, after 48 h, a further 55 ml of concentrated hydrochloric acid were added. After cooling, the reaction mixture was poured into 200 ml of water and the product was extracted twice in 300 ml of ether. The combined extracts were washed with 100 ml of water and 25 ml of saturated sodium chloride solution, dried over sodium sulfate and concentrated on a rotary evaporator. After flash chromatography (pentane/ether, 9:1, Rf=0.23) on silica gel, 19.6 g (75%) of 5,6-dimethoxy-1-methylindane were obtained.

Source