tert-Butyl piperazine-1-carboxylate → 4-[3-Methyl-7-(2-butynyl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-8-yl]piperazine-1-carboxylic acid tert-butyl ester

HRID 1792010Notes

Reaction equation

HRID 1792010 reaction equation
[CH2:1]([N:5]1[C:13]2[C:12](=[O:14])[NH:11][C:10](=[O:15])[N:9]([CH3:16])[C:8]=2[N:7]=[C:6]1Cl)[C:2]#[C:3][CH3:4].[C:18]([O:22][C:23]([N:25]1[CH2:30][CH2:29][NH:28][CH2:27][CH2:26]1)=[O:24])([CH3:21])([CH3:20])[CH3:19]>>[C:18]([O:22][C:23]([N:25]1[CH2:30][CH2:29][N:28]([C:6]2[N:5]([CH2:1][C:2]#[C:3][CH3:4])[C:13]3[C:12](=[O:14])[NH:11][C:10](=[O:15])[N:9]([CH3:16])[C:8]=3[N:7]=2)[CH2:27][CH2:26]1)=[O:24])([CH3:21])([CH3:19])[CH3:20]

Participants

3

Reactant 2

HCID 143452tert-Butyl piperazine-1-carboxylateHCID 220298307-(But-2-YN-1-YL)-8-chloro-3-methyl-3,7-dihydro-1H-purine-2,6-dione

Product 1

HCID 230818994-[3-Methyl-7-(2-butynyl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-8-yl]piperazine-1-carboxylic acid tert-butyl esterYield 49.3%

Procedure

3-Methylxanthine (1.1 g) was dissolved in N,N-dimethylformamide (15 ml), and potassium carbonate (1.0 g) and 1-bromo-2-butyne (0.64 ml) were added thereto. After stirring at room temperature overnight, the reaction mixture was diluted with ethyl acetate, and washed with water. Insoluble white solid was collected by filtration, and washed with ethyl acetate to give 1.3 g of 7-(2-butynyl)-3-methyl-3,7-dihydropurine-2,6-dione. Then, the resulting 7-(2-butynyl)-3-methyl-3,7-dihydropurine-2,6-dione (1.3 g) was dissolved in N,N-dimethylformamide (15 ml), and N-chlorosuccinimide (0.89 g) was added while cooling on ice. After stirring at room temperature for 3 hours, the reaction mixture was diluted with ethyl acetate, and washed with water. Insoluble white solid was collected by filtration, and washed with ethyl acetate to give 1.1 g of 7-(2-butynyl)-8-chloro-3-methyl-3,7-dihydropurine-2,6-dione. The resulting 7-(2-butynyl)-8-chloro-3-methyl-3,7-dihydropurine-2,6-dione (1.4 g) and 1-piperazine carboxylic acid tert-butyl ester (2.8 g) were stirred at 150° C. for 1 hour. After cooling to room temperature, the reaction mixture was extracted with ethyl acetate, then the organic layer was washed with water and saturate brine, and was dried over anhydrous magnesium sulfate. The solvent was removed by distillation at reduced pressure. The residue was purified by silica gel column chromatography to obtain 1.1 g of the title compound from a fraction eluted with hexane-ethyl acetate (1:4).

Workup

  1. extractionthe reaction mixture was extracted with ethyl acetate
  2. washthe organic layer was washed with water
  3. concentrationsaturate brine
  4. dry with materialwas dried over anhydrous magnesium sulfate
  5. customThe solvent was removed by distillation at reduced pressure
  6. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-1b120fbfc5814f7b8398ed8a595df3b1
Source dataset
uspto-grants-2006_07
Patent number
US07074798B2

Reaction notes

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