Diisopropylethylamine → 3-(2-Ethyl-4-{5-[2-(ethyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionic acid tert-butyl ester

HRID 2047312Notes

Reaction equation

HRID 2047312 reaction equation
[CH2:1]([N:3]([CH3:14])[C:4]1[CH:5]=[C:6]([CH:10]=[C:11]([CH3:13])[N:12]=1)[C:7]([OH:9])=O)[CH3:2].CCN(C(C)C)C(C)C.C1CN([P+](ON2N=NC3C=CC=CC2=3)(N2CCCC2)N2CCCC2)CC1.F[P-](F)(F)(F)(F)F.[C:57]([O:61][C:62](=[O:78])[CH2:63][CH2:64][C:65]1[C:70]([CH3:71])=[CH:69][C:68]([C:72](=[NH:75])[NH:73]O)=[CH:67][C:66]=1[CH2:76][CH3:77])([CH3:60])([CH3:59])[CH3:58]>CN(C=O)C.O.C([O-])(O)=O.[Na+].O1CCOCC1>[C:57]([O:61][C:62](=[O:78])[CH2:63][CH2:64][C:65]1[C:70]([CH3:71])=[CH:69][C:68]([C:72]2[N:73]=[C:7]([C:6]3[CH:10]=[C:11]([CH3:13])[N:12]=[C:4]([N:3]([CH2:1][CH3:2])[CH3:14])[CH:5]=3)[O:9][N:75]=2)=[CH:67][C:66]=1[CH2:76][CH3:77])([CH3:60])([CH3:59])[CH3:58]

Participants

9

Reactant 4

HCID 81531DiisopropylethylamineHCID 2724699PyBOPHCID 584180642-(Ethyl-methyl-amino)-6-methyl-isonicotinic acidHCID 178436624tert-butyl 3-[2-ethyl-4-[(Z)-N'-hydroxycarbamimidoyl]-6-methylphenyl]propanoate

Product 1

HCID 685784423-(2-Ethyl-4-{5-[2-(ethyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionic acid tert-butyl ester

Reagents, catalysts & solvents 4

HCID 962WaterSolventHCID 6228DimethylformamideSolventHCID 312751,4-DioxaneSolventHCID 516892Sodium BicarbonateSolvent

Procedure

To a solution of 2-(ethyl-methyl-amino)-6-methyl-isonicotinic acid (106 mg, 0.459 mmol) and DIPEA (178 mg, 1.38 mmol) in DMF (2 mL) is added PyBOP (253 mg, 0.486 mmol) at 0° C. The mixture is stirred for 15 min at 0° C. before 3-[2-ethyl-4-(N-hydroxycarbamimidoyl)-6-methyl-phenyl]-propionic acid tert-butyl ester (140 mg, 0.459 mmol) is added. Stirring is continued for 1 h at 0° C. The reaction mixture is diluted with water (2 mL) and sat. aq. NaHCO3-solution and extracted three times with diethyl ether. The combined org. extracts are dried over MgSO4, filtered and concentrated to give the crude hydroxyamidine ester intermediate; LC-MS: tR=0.92 min; [M+1]+=483.22. This material is dissolved in dioxane and then stirred at 80° C. for 15 h. The solvent is removed in vacuo to give crude 3-(2-ethyl-4-{5-[2-(ethyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionic acid tert-butyl ester; LC-MS: tR=1.03 min; [M+1]+=463.31. The crude ester is dissolved in 6 N aq. HCl (10 mL) and stirred at 65° C. for 18 h. The mixture is concentrated and the crude product is purified by prep. TLC using DCM containing 11% of methanol as eluent to give 3-(2-ethyl-4-{5-[2-(ethyl-methyl-amino)-6-methyl-pyridin-4-yl]-[1,2,4]oxadiazol-3-yl}-6-methyl-phenyl)-propionic acid (5 mg) as a yellow resin; LC-MS: tR=0.89 min; [M+1]+=409.19.

Workup

  1. additionis added
  2. extractionextracted three times with diethyl ether
  3. dry with materialextracts are dried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customto give the crude hydroxyamidine ester intermediate
  7. stirringstirred at 80° C. for 15 h
  8. customThe solvent is removed in vacuo

Sources & evidence

ORD record
ord-0b3b9757e3694ddbb2ef1948e4c44c68
Source dataset
uspto-grants-2013_11
Patent number
US08592460B2

Reaction notes

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