Potassium Carbonate → 2,6-Bis(2-pyridyl)-4(1H)-pyridone

HRID 268581

Reaction equation

HRID 268581 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[C:7]1[NH:8][C:9]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=2)=[CH:10][C:11](=[O:13])[CH:12]=1.P(Br)(Br)(Br)(Br)[Br:21].P(Br)(Br)(Br)=O.C([O-])([O-])=O.[K+].[K+]>>[Br:21][C:11]1[CH:12]=[C:7]([C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][N:1]=2)[N:8]=[C:9]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=2)[CH:10]=1.[N:1]1[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[C:7]1[NH:8][C:9]([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][N:15]=2)=[CH:10][C:11](=[O:13])[CH:12]=1

Participants

6

Reactant 4

HCID 11430Potassium CarbonateHCID 24613Phosphorus oxybromideHCID 62678Phosphorus pentabromideHCID 6193532,6-Bis(2-pyridyl)-4(1H)-pyridone

Product 2

HCID 6193532,6-Bis(2-pyridyl)-4(1H)-pyridoneHCID 106149954'-Bromo-2,2':6',2''-terpyridine

Conditions

Temperature
100 °C

Procedure

A 500 mL flask was charged with 2,6-bis-pyridyl-4-(1H)-pyridone (2.47 g, 9.9 mmol), phosphorus pentabromide (6.6 g, 15.4 mmol), and phosphorus oxybromide (30 g) and heated to 100° C. with stirring for 12 h, giving a black oily residue. The reaction was cooled to room temperature; ice was added cautiously to the reaction until the evolution of gas subsided. The reaction mixture was neutralized with K2CO3 (aq), extracted with CH2Cl2 (3×300 mL), dried over MgSO4, and filtered. Removal of solvent gave a tan colored solid which was purified by column chromatography on neutral alumina using 2:1 CH2Cl2:hexanes as the eluant, providing 2.65 g of pure 4′-bromo-2,2′;6′,2″-terpyridine (86% yield, based on 2.47 g of the 2,6-bis-pyridyl-4-(1H)-pyridone starting material). 1H-NMR (250 MHz, CDCl3): 8.68 (dq, 2 H, J=4.7 Hz, 0.8 Hz), 8.62 (s, 2 H), 8.56 (dt, 2 H, J=8.0 Hz, 1.0 Hz), 7.84 (td, J=7.7 Hz, 1.7 Hz), 7.33 (ddd, 2 H, J=7.6 Hz, 4.9 Hz, 1.2 Hz). HRMS (ESI+) m/z: 333.9955 (calcd for C15H10N3BrNa (M+Na)+ 333.9956).

Workup

  1. customgiving a black oily residue
  2. temperatureThe reaction was cooled to room temperature
  3. additionice was added cautiously to the reaction until the evolution of gas
  4. extractionextracted with CH2Cl2 (3×300 mL)
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. customRemoval of solvent
  8. customgave a tan colored solid which
  9. customwas purified by column chromatography on neutral alumina using 2:1 CH2Cl2

Sources & evidence

ORD record
ord-f3a74ced325b455ea8fd348de017c3f6
Source dataset
uspto-grants-2008_11
Patent number
US07445845B2

Linked notes

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