Water → 1-(imidazolin-2-yl)-4-Boc-piperazine

HRID 650890Notes

Reaction equation

HRID 650890 reaction equation
[C:1]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].O.C([O-])([O-])=O.[K+].[K+].[NH:21]1[CH2:25][CH2:24][N:23]=[C:22]1S(O)(=O)=O>CO>[NH:23]1[CH2:24][CH2:25][N:21]=[C:22]1[N:11]1[CH2:10][CH2:9][N:8]([C:1]([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2])[CH2:13][CH2:12]1

Participants

6

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 143452tert-Butyl piperazine-1-carboxylateHCID 2745614,5-dihydro-1H-imidazole-2-sulfonic acid

Product 1

HCID 184241321-(imidazolin-2-yl)-4-Boc-piperazine

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

1.86 of Boc-piperazine were combined with 25 ml of water, 25 ml of methanol, 2.77 g of K2CO3 and 1.5 g of imidazoline-2-sulphonic acid and stirred for 2 days at RT. After dilution with water the mixture was extracted with EE and chromatographed over silica gel. 0.8 g of 1-(imidazolin-2-yl)-4-Boc-piperazine were obtained. This substance was combined with 6.2 ml of DMF and 136 mg of NaH dispersion (60%). After one hour, 0.214 ml of methyl iodide was added dropwise and the reaction mixture was left for three days at RT. It was combined with water, extracted with EE and chromatographed over silica gel. In this way, 0.47 g of 1-(1-methylimidazolin-2-yl)-4-Boc -piperazine was obtained, which was treated with 5 ml of 4N HCl in dioxane at RT. After one hour, the mixture was concentrated by evaporation, stirred with ether and evaporated to dryness in vacuo. 0.38 g of 1-(1-methyl -imidazolin-2-yl)-piperazine dihydrochloride was thus obtained as a solid substance (yield 15%).

Workup

  1. extractionAfter dilution with water the mixture was extracted with EE
  2. customchromatographed over silica gel

Sources & evidence

ORD record
ord-780b163fe0994dfc83742ae3532af642
Source dataset
uspto-grants-2001_08
Patent number
US06277840B1

Reaction notes

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