4-Isobutylbenzoic acid → Ethyl 5-[5-(4-isobutylphenyl)-1,2,4-oxadiazol-3-yl]pyrazine-2-carboxylate

HRID 2242224Notes

Reaction equation

HRID 2242224 reaction equation
[CH2:1]([C:5]1[CH:13]=[CH:12][C:8]([C:9]([OH:11])=O)=[CH:7][CH:6]=1)[CH:2]([CH3:4])[CH3:3].ON1C2C=CC=CC=2N=N1.F[B-](F)(F)F.N1(OC(N(C)C)=[N+](C)C)C2C=CC=CC=2N=N1.C(N(C(C)C)CC)(C)C.[NH2:55][C:56](=[N:68]O)[C:57]1[N:58]=[CH:59][C:60]([C:63]([O:65][CH2:66][CH3:67])=[O:64])=[N:61][CH:62]=1>O1CCOCC1>[CH2:1]([C:5]1[CH:6]=[CH:7][C:8]([C:9]2[O:11][N:55]=[C:56]([C:57]3[N:58]=[CH:59][C:60]([C:63]([O:65][CH2:66][CH3:67])=[O:64])=[N:61][CH:62]=3)[N:68]=2)=[CH:12][CH:13]=1)[CH:2]([CH3:3])[CH3:4]

Participants

7

Reactant 5

HCID 381114-Isobutylbenzoic acidHCID 757711-HydroxybenzotriazoleHCID 81531DiisopropylethylamineHCID 2733207O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborateHCID 136368376Ethyl 5-[amino(hydroxyimino)methyl]pyrazine-2-carboxylate

Product 1

HCID 59204302Ethyl 5-[5-(4-isobutylphenyl)-1,2,4-oxadiazol-3-yl]pyrazine-2-carboxylateYield 27.1%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

A mixture of 4-isobutylbenzoic acid (0.28 g, 1.59 mmol), 1-hydroxybenzotriazole (0.042 g, 0.31 mmol), N-[(1H-1,2,3-benzotriazol-1-yloxy)(dimethylamino)methylene]-N-methylmethanaminium tetrafluoroborate (0.51 g, 1.59 mmol), diisopropylethylamine (1.4 mL, 7.86 mmol) and dioxane (4 mL) was stirred at room temperature for 1 hour. Ethyl 5-[amino(hydroxyimino)methyl]pyrazine-2-carboxylate (0.33 g, 1.57 mmol) was added to the reaction mixture, stirred for 1.5 hours at room temperature and 6 hours at 100° C. The reaction mixture was cooled to room temperature, quenched with H2O (10 mL) and filtered. The precipitate was dissolved in EtOAc (10 mL), washed with 1N NaOH (3×10 mL) and brine (2×10 mL), dried (Na2SO4), filtered and concentrated in vacuo to yield the title compound (0.15 g, 27%) as a white solid.

Workup

  1. stirringstirred for 1.5 hours at room temperature and 6 hours at 100° C
  2. temperatureThe reaction mixture was cooled to room temperature
  3. customquenched with H2O (10 mL)
  4. filtrationfiltered
  5. dissolutionThe precipitate was dissolved in EtOAc (10 mL)
  6. washwashed with 1N NaOH (3×10 mL) and brine (2×10 mL)
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-7ac23ec1106e409ca21bba6bb7fe27f3
Source dataset
uspto-grants-2010_03
Patent number
US07671043B2

Reaction notes

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