N-bromobutanimide → 5-Bromo-2-methyl-6-oxo-1-phenyl-1,6-dihydro-pyridine-3-carboxylic acid methyl ester

HRID 919869Notes

Reaction equation

HRID 919869 reaction equation
C[O:2][C:3](=O)[CH:4]=[CH:5][C:6](=[C:12]([NH:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[CH3:13])[C:7]([O:9][CH2:10]C)=[O:8].C[O-].[Na+].[Br:25]N1C(=O)CCC1=O>CO>[CH3:10][O:9][C:7]([C:6]1[CH:5]=[C:4]([Br:25])[C:3](=[O:2])[N:14]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C:12]=1[CH3:13])=[O:8]

Participants

5

Reactant 3

HCID 67184N-bromobutanimideHCID 10942334Sodium MethoxideHCID 867141384-(1-Phenylamino-ethylidene)-pent-2-enedioic acid 5-ethyl ester 1-methyl ester

Product 1

HCID 682971985-Bromo-2-methyl-6-oxo-1-phenyl-1,6-dihydro-pyridine-3-carboxylic acid methyl esterYield 38.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

MeOH (200 mL) was added to a flask containing 4-(1-phenylamino-ethylidene)-pent-2-enedioic acid 5-ethyl ester 1-methyl ester (5.88 g, 20.3 mmol). NaOMe solution (4.7 mL, 20.3 mmol, 4.375 M in MeOH) and N-bromosuccinimide (4.35 g, 24.4 mmol) were added, and the resulting mixture was refluxed for 1 h. After cooling to r.t., the solvent was evaporated in vacuo. The residue was partitioned between saturated NH4Cl and CH2Cl2. The aqueous layer was extracted with additional CH2Cl2 and the organic layers were combined, dried over MgSO4, and concentrated. The crude product was chromatographed (0-45% EtOAc/hexanes) to give 2.51 g of the title compound (containing about 14% of the corresponding ethyl ester) as a yellow solid. MS: (+) m/z 343.93, 346.07 (M+Na, 79/81Br).

Workup

  1. temperaturethe resulting mixture was refluxed for 1 h
  2. customthe solvent was evaporated in vacuo
  3. customThe residue was partitioned between saturated NH4Cl and CH2Cl2
  4. extractionThe aqueous layer was extracted with additional CH2Cl2
  5. dry with materialdried over MgSO4
  6. concentrationconcentrated
  7. customThe crude product was chromatographed (0-45% EtOAc/hexanes)
  8. customto give

Sources & evidence

ORD record
ord-055c076d29ca417782d546c8c42b9ba0
Source dataset
uspto-grants-2016_03
Patent number
US09271970B2

Reaction notes

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