1,3-Dibromopropane → 1-[4-(3-Bromopropoxy)-3-methylphenyl]ethanone

HRID 233160

Reaction equation

HRID 233160 reaction equation
[CH3:1][C:2]1[CH:7]=[C:6]([C:8]([CH3:10])=[O:9])[CH:5]=[CH:4][C:3]=1[OH:11].C([O-])([O-])=O.[K+].[K+].[Br:18][CH2:19][CH2:20][CH2:21]Br>C(#N)C>[Br:18][CH2:19][CH2:20][CH2:21][O:11][C:3]1[CH:4]=[CH:5][C:6]([C:8](=[O:9])[CH3:10])=[CH:7][C:2]=1[CH3:1]

Participants

5

Procedure

A mixture of 4-hydroxy-3-methylacetophenone (14.5 g, 96 mmol), K2CO3 (17.5 g, 144 mmol), and 1,3-dibromopropane (30 g, 144 mmol) in acetonitrile (400 ml) was heated at reflux for 6 hours. At the end of the reaction, the solvent was removed on a rotary evaporator, and the crude solid was extracted into dichloromethane (750 ml). The insoluble inorganics were filtered off. The dichloromethane solution was concentrated again to a crude oil (34.5 g). Purification was effected by flash chromatography over a silica gel column (SiO2, 150 g; eluted with 7:3 hexane:dichloromethane, 2 l; and dichloromethane 2 l). The material thus purified weighed 14.6 g (56%) and was recrystallized from ethanol. Recrystallization again from ethanol gave analytically pure 1-[4-(3-bromopropoxy)-3-methylphenyl]ethanone, m.p.=59°-61° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 6 hours
  3. customAt the end of the reaction
  4. customthe solvent was removed on a rotary evaporator
  5. extractionthe crude solid was extracted into dichloromethane (750 ml)
  6. filtrationThe insoluble inorganics were filtered off
  7. concentrationThe dichloromethane solution was concentrated again to a crude oil (34.5 g)
  8. customPurification
  9. washwas effected by flash chromatography over a silica gel column (SiO2, 150 g; eluted with 7:3 hexane:dichloromethane, 2 l; and dichloromethane 2 l)
  10. customThe material thus purified
  11. customwas recrystallized from ethanol
  12. customRecrystallization again from ethanol

Sources & evidence

ORD record
ord-e9f21ffe3846464cba8dbc6267eeeb06
Source dataset
uspto-grants-1997_01
Patent number
US05591745

Linked notes

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