Cesium carbonate → Diethyl 4-(2,4,6-trimethoxyphenyl)pyridine-2,6-dicarboxylate

HRID 1097175Notes

Reaction equation

HRID 1097175 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[C:7]([O:9][CH3:10])[CH:6]=[C:5]([O:11][CH3:12])[C:4]=1B(O)O.Br[C:17]1[CH:22]=[C:21]([C:23]([O:25][CH2:26][CH3:27])=[O:24])[N:20]=[C:19]([C:28]([O:30][CH2:31][CH3:32])=[O:29])[CH:18]=1.C(=O)([O-])[O-].[Cs+].[Cs+]>CN(C=O)C.[Pd].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[CH3:1][O:2][C:3]1[CH:8]=[C:7]([O:9][CH3:10])[CH:6]=[C:5]([O:11][CH3:12])[C:4]=1[C:17]1[CH:18]=[C:19]([C:28]([O:30][CH2:31][CH3:32])=[O:29])[N:20]=[C:21]([C:23]([O:25][CH2:26][CH3:27])=[O:24])[CH:22]=1

Participants

6

Reactant 3

HCID 10796Cesium carbonateHCID 41979962,4,6-Trimethoxyphenylboronic acidHCID 13794409Diethyl 4-bromopyridine-2,6-dicarboxylate

Product 1

HCID 66814130Diethyl 4-(2,4,6-trimethoxyphenyl)pyridine-2,6-dicarboxylate

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 6228DimethylformamideSolvent

Conditions

Temperature
95 °C

Procedure

2,4,6-trimethoxyphenylboronic acid (2.12 g, 10.0 mmol) and diethyl 4-bromopyridine-2,6-dicarboxylate (3.33 g, 11.0 mmol) were dissolved in dry DMF (50 mL). Caesium carbonate (4.56 g, 14.0 mmol) and tetrakis(triphenylphosphine)-palladium(0) (0.23 g, 0.20 mmol) were added, and the mixture was deaerated with argon. The mixture was heated at 95° C. for 48 h. The mixture was allowed to cool to room temperature and filtered. The filtrate was concentrated in vacuo, the residue was dissolved in chloroform (60 mL) and washed with 10% aq. citric acid and water, dried over Na2SO4 and concentrated. Purification was performed on silica gel (eluent petroleum ether bp 40-60° C.; ethyl acetate 5:3→2:5, v/v). Yield was 2.09 g (54%). 1H NMR (CDCl3): δ 1.45 (6H, t, J 7.1); 3.74 (6H, s); 3.90 (3H, s); 4.49 (4H, q, J 7.1); 6.22 (2H, s); 8.28 (2H, s). IR (film)/cm−1 1743, 1610 (C═O); 1339, 1238, 1128 (C—O). ESI-MS: [M+H]+ 390.19 calc. for C20H24NO7+ 390.15.

Workup

  1. temperatureto cool to room temperature
  2. filtrationfiltered
  3. concentrationThe filtrate was concentrated in vacuo
  4. dissolutionthe residue was dissolved in chloroform (60 mL)
  5. washwashed with 10% aq. citric acid and water
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated
  8. customPurification

Sources & evidence

ORD record
ord-a71d2297210b40d9bf7bb0013ffbb2b2
Source dataset
uspto-grants-2012_03
Patent number
US08143057B2

Reaction notes

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