Propanal → N-(8-(2,4-dichlorophenyl)-2-ethylimidazo[1,2-a]pyrazin-3-yl]-N,N-dipropylamine

HRID 501014Notes

Reaction equation

HRID 501014 reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[C:9]1[C:10]2[N:11]([C:15]([NH:20][CH2:21][CH2:22][CH3:23])=[C:16]([CH2:18][CH3:19])[N:17]=2)[CH:12]=[CH:13][N:14]=1.[CH:24](=O)[CH2:25][CH3:26].S(=O)(=O)(O)O.[BH4-].[Na+].[OH-].[Na+]>O1CCCC1.O>[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[C:9]1[C:10]2[N:11]([C:15]([N:20]([CH2:24][CH2:25][CH3:26])[CH2:21][CH2:22][CH3:23])=[C:16]([CH2:18][CH3:19])[N:17]=2)[CH:12]=[CH:13][N:14]=1

Participants

8

Reactant 5

HCID 527PropanalHCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 4311764Sodium borohydrideHCID 22024528HCID 22024528, compound

Product 1

HCID 22024404N-(8-(2,4-dichlorophenyl)-2-ethylimidazo[1,2-a]pyrazin-3-yl]-N,N-dipropylamineYield 81.8%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

N-[8-(2,4-Dichlorophenyl)-2-ethylimidazo[1,2-a]pyrazin-3-yl]-N-propylamine (296 mg, 0.85 mmol) and propionaldehyde (0.19 mL, 2.6 mmol) were dissolved in tetrahydrofuran (1.1 mL), and 3M sulfuric acid (0.87 mL, 2.6 mmol) was added thereto. Sodium borohydride (70 mg) was added thereto under ice-cooling, and the mixture was stirred for 3 hours. Water was added to the reaction mixture, which was neutralized with a 2N aqueous sodium hydroxide solution and extracted with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and evaporated. The resulting residue was purified by silica gel column chromatography (ethyl acetate:n-hexane=1:2) to give N-[8-(2,4-dichlorophenyl)-2-ethylimidazo[1,2-a]pyrazin-3-yl]-N,N-dipropylamine (272 mg) as pale yellow crystals. The resulting free compound was converted into hydrochloride with hydrochloric acid-ether using the conventional method, to give the title compound (250 mg) as white crystals.

Workup

  1. temperatureunder ice-cooling
  2. extractionextracted with ethyl acetate
  3. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
  4. customevaporated
  5. customThe resulting residue was purified by silica gel column chromatography (ethyl acetate:n-hexane=1:2)

Sources & evidence

ORD record
ord-9e64cf8c04e640b892b9ce8cdc4340d3
Source dataset
uspto-grants-2010_08
Patent number
US07772249B2

Reaction notes

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