Potassium Carbonate → 5-Chloro-4-methoxy-2-vinyl-pyridine

HRID 1908814Notes

Reaction equation

HRID 1908814 reaction equation
Cl[C:2]1[CH:7]=[C:6]([O:8][CH3:9])[C:5]([Cl:10])=[CH:4][N:3]=1.B1(C=C)OB([CH:17]=[CH2:18])OB(C=C)O1.C1C=CN=CC=1.C([O-])([O-])=O.[K+].[K+]>COCCOC.CC(=O)OCC.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[Cl:10][C:5]1[C:6]([O:8][CH3:9])=[CH:7][C:2]([CH:17]=[CH2:18])=[N:3][CH:4]=1

Participants

7

Reactant 3

HCID 11430Potassium CarbonateHCID 27348062,4,6-Trivinylboroxin-Pyridine ComplexHCID 714638062,5-Dichloro-4-methoxypyridine

Product 1

HCID 670268745-Chloro-4-methoxy-2-vinyl-pyridineYield 57.8%

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalystHCID 80711,2-DimethoxyethaneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

To a solution of 2,5-dichloro-4-methoxy-pyridine (730 mg, 4.10 mmol) in DME (16 mL), 2,4,6-trivinylcyclotriboroxane pyridine complex (987 mg, 4.10 mmol) followed by 2 M aq. K2CO3 solution (4 mL) is added. The solution is degassed and put under argon before Pd(PPh3)4 (95 mg, 82 μmol) is added. The mixture is stirred for 18 h at 80° C. The mixture is cooled to rt, diluted with EA (200 mL) and washed with water and sat. aq. NaHCO3 solution. The org. extract is dried over MgSO4, filtered and concentrated. The remaining brown residue is purified by CC on silica gel eluting with heptane:EA 9:1 to give 5-chloro-4-methoxy-2-vinyl-pyridine (402 mg) as a pale yellow oil; LC-MS: tR=0.53 min, [M+1]+=169.98; 1H NMR (CDCl3): δ 3.98 (s, 3H), 5.52 (d, J=10.5 Hz, 1H), 6.20 (d, J=17.3 Hz, 1H), 6.76 (dd, J=17.3, 10.8 Hz, 1H), 6.88 (s, 1H), 8.41 (s, 1H).

Workup

  1. additionis added
  2. customThe solution is degassed
  3. additionis added
  4. temperatureThe mixture is cooled to rt
  5. washwashed with water and sat. aq. NaHCO3 solution
  6. extractionextract
  7. dry with materialis dried over MgSO4
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe remaining brown residue is purified by CC on silica gel eluting with heptane:EA 9:1

Sources & evidence

ORD record
ord-1a5bc6e2735a43abb55a9707058a411c
Source dataset
uspto-grants-2013_12
Patent number
US08598208B2

Reaction notes

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