1,5-Dibromopentane → N-(5-Bromopentyl)phthalimide

HRID 1169123Notes

Reaction equation

HRID 1169123 reaction equation
[C:1]1(=[O:11])[NH:5][C:4](=[O:6])[C:3]2=[CH:7][CH:8]=[CH:9][CH:10]=[C:2]12.[K].[Br:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18]Br>CN(C)C=O>[Br:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][N:5]1[C:1](=[O:11])[C:2]2=[CH:10][CH:9]=[CH:8][CH:7]=[C:3]2[C:4]1=[O:6]

Participants

4

Reactant 2

HCID 81001,5-DibromopentaneHCID 24194345Phthalimide potassium salt

Product 1

HCID 136770N-(5-Bromopentyl)phthalimide

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

3.70 g of potassium phthalimide was dissolved in 20 ml of N,N-dimethylformamide; 5.4 ml of 1,5-dibromopentane was added, followed by stirring at room temperature for 15 hours. Ice water was added to the reaction mixture, followed by extraction with ethyl acetate; the extract was washed with saline, dried over magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography and eluted with hexane-ethyl acetate (4:1). The desired fraction was collected to yield 4.68 g of N-(5-bromopentyl)phthalimide as an oily substance. 4.68 g of N-(5-bromopentyl)phthalimide and 4.25 g of 4-(diphenylmethoxy)piperidine were dissolved in 30 ml of N,N-dimethylformamide; 2.42 g of potassium carbonate was added, followed by stirring at room temperature for 15 hours. Ice water was added to the reaction mixture, followed by extraction with ethyl acetate; the extract was washed with saline, dried over magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography and eluted with hexane-ethyl acetate-triethylamine (50:50:1). The desired fraction was collected to yield 6.67 g of N-[5-[4-(diphenylmethoxy)piperidino]pentyl]phthalimide as an oily substance. 6.6 g of N-[5-[4-(diphenylmethoxy)piperidino]pentyl]phthalimide was dissolved in 30 ml of ethanol; 0.694 ml of hydrazine monohydrate was added, followed by thermal refluxing for 3 hours. After cooling, the mixture was concentrated under reduced pressure; ethyl acetate was added to the residue; the crystal precipitated was collected, dissolved in 15 ml of a 1N aqueous solution of sodium hydroxide and 20 ml of water and extracted with ethyl acetate; the extract was washed with saline, dried over sodium sulfate and concentrated under reduced pressure; the crystal obtained was collected to yield 3.29 g of the title compound.

Workup

  1. extractionfollowed by extraction with ethyl acetate
  2. washthe extract was washed with saline
  3. dry with materialdried over magnesium sulfate
  4. concentrationconcentrated under reduced pressure
  5. washeluted with hexane-ethyl acetate (4:1)
  6. customThe desired fraction was collected

Sources & evidence

ORD record
ord-0419e01f85cd4e74873bc10a53a02740
Source dataset
uspto-grants-2003_09
Patent number
US06627630B1

Reaction notes

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