Pyridine → Isobutyric acid 5-methyl-7-(3-methyl-1,2,4-oxadiazol-5-yl)-6-oxo-5,6-dihydro-pyrido[2,3-b]pyrazin-8-yl ester

HRID 241782Notes

Reaction equation

HRID 241782 reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[N:7][CH:8]=[CH:9][N:10]=2)[N:5]([CH3:12])[C:4](=[O:13])[C:3]=1[C:14]1[O:18][N:17]=[C:16]([CH3:19])[N:15]=1.N1C=CC=CC=1.[C:26](Cl)(=[O:30])[CH:27]([CH3:29])[CH3:28]>ClCCl>[CH3:12][N:5]1[C:6]2=[N:7][CH:8]=[CH:9][N:10]=[C:11]2[C:2]([O:1][C:26](=[O:30])[CH:27]([CH3:29])[CH3:28])=[C:3]([C:14]2[O:18][N:17]=[C:16]([CH3:19])[N:15]=2)[C:4]1=[O:13]

Participants

5

Reactant 3

HCID 1049PyridineHCID 62325Isobutyryl chlorideHCID 1360134288-hydroxy-5-methyl-7-(3-methyl-1,2,4-oxadiazol-5-yl)-5H-pyrido[2,3-b]pyrazin-6-one

Product 1

HCID 58114923Isobutyric acid 5-methyl-7-(3-methyl-1,2,4-oxadiazol-5-yl)-6-oxo-5,6-dihydro-pyrido[2,3-b]pyrazin-8-yl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 8-hydroxy-5-methyl-7-(3-methyl-1,2,4-oxadiazol-5-yl)-5H-pyrido[2,3-b]pyrazin-6-one (Example 7.4) (0.044 g) and pyridine (0.018 ml) in dichloromethane (1 ml) was added dropwise isobutyryl chloride (0.022 ml). The reaction mixture was stirred at ambient temperature for 4 hours and then stored at ambient temperature for 16 hours. The reaction mixture was diluted with more dichloromethane and the mixture was washed successively with aqueous sodium hydrogen carbonate (saturated), aqueous ammonium chloride (saturated) and brine. The organic fraction was dried over magnesium sulfate and concentrated. The residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane 1:1) to give Compound No. B6 of Table 6 as a pale yellow solid (0.020 g).

Workup

  1. waitstored at ambient temperature for 16 hours
  2. washthe mixture was washed successively with aqueous sodium hydrogen carbonate (saturated), aqueous ammonium chloride (saturated) and brine
  3. dry with materialThe organic fraction was dried over magnesium sulfate
  4. concentrationconcentrated
  5. customThe residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane 1:1)
  6. customto give Compound No

Sources & evidence

ORD record
ord-9578131821764c0ebae9d5605c881c98
Source dataset
uspto-grants-2014_02
Patent number
US08653078B2

Reaction notes

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