1,5-Dibromopentane → 5-Chloro-3-methyl-6-(piperidin-1-yl)-benzofuran

HRID 637685Notes

Reaction equation

HRID 637685 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][C:12]=1[Cl:13])[O:5][CH2:6][C:7](=O)[CH3:8].Br[CH2:15][CH2:16][CH2:17][CH2:18][CH2:19]Br.C(N(C(C)C)C(C)C)C>C(O)C>[Cl:13][C:12]1[C:2]([N:1]2[CH2:19][CH2:18][CH2:17][CH2:16][CH2:15]2)=[CH:3][C:4]2[O:5][CH:6]=[C:7]([CH3:8])[C:10]=2[CH:11]=1

Participants

5

Reactant 3

HCID 81001,5-DibromopentaneHCID 81531DiisopropylethylamineHCID 202556581-(3-Amino-4-chlorophenoxy)-2-propanone

Product 1

HCID 202556485-Chloro-3-methyl-6-(piperidin-1-yl)-benzofuran

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 9.98 g (50 mmole) of 1-(3-amino-4-chlorophenoxy)-2-propanone, 22.9 g (0.10 mole) of 1,5-dibromopentane, 12.9 g (0.10 mole) of N-ethyldiisopropylamine and 60 ml of ethanol is boiled under reflux for 18 hours. The residue obtained after concentration by evaporation in vacuo is taken up in methylene chloride and washed twice with dilute sodium bicarbonate solution. The organic phase is dried, concentrated by evaporation and the crude product is taken up in 250 ml of ethanol, 40 ml of concentrated hydrochloric acid are added and the whole is boiled under reflux for 30 hours. The ethanol is concentrated in a vacuum rotary evaporator and the residue is diluted with ice-water, rendered alkaline with 6N sodium hydroxide solution and extracted with methylene chloride. The organic phases are washed with water, combined, dried over sodium sulphate and concentrated in a vacuum rotary evaporator. Chromatography over silica gel using chloroform as eluant yields 5-chloro-3-methyl-6-(piperidin-1-yl)-benzofuran which, after recrystallisation from petroleum ether, melts at 82°-84°.

Workup

  1. temperatureunder reflux for 18 hours
  2. customThe residue obtained
  3. concentrationafter concentration
  4. customby evaporation in vacuo
  5. washwashed twice with dilute sodium bicarbonate solution
  6. customThe organic phase is dried
  7. concentrationconcentrated by evaporation
  8. addition40 ml of concentrated hydrochloric acid are added
  9. temperatureunder reflux for 30 hours
  10. concentrationThe ethanol is concentrated in a vacuum rotary evaporator
  11. additionthe residue is diluted with ice-water
  12. extractionextracted with methylene chloride
  13. washThe organic phases are washed with water
  14. dry with materialdried over sodium sulphate
  15. concentrationconcentrated in a vacuum rotary evaporator

Sources & evidence

ORD record
ord-d128579c1e894e228cc3fad39070462d
Source dataset
uspto-grants-1985_12
Patent number
US04558043

Reaction notes

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