Potassium Carbonate → 4-(4-(Trifluoromethyl)phenyl)pyridine 1-oxide

HRID 882040Notes

Reaction equation

HRID 882040 reaction equation
Cl[C:2]1[CH:7]=[CH:6][N+:5]([O-:8])=[CH:4][CH:3]=1.[F:9][C:10]([F:21])([F:20])[C:11]1[CH:16]=[CH:15][C:14](B(O)O)=[CH:13][CH:12]=1.C([O-])([O-])=O.[K+].[K+]>CS(C)=O.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2]>[F:9][C:10]([F:21])([F:20])[C:11]1[CH:16]=[CH:15][C:14]([C:2]2[CH:7]=[CH:6][N+:5]([O-:8])=[CH:4][CH:3]=2)=[CH:13][CH:12]=1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 707244-chloropyridine N-oxideHCID 27343894-(Trifluoromethyl)phenylboronic acid

Product 1

HCID 573508294-(4-(Trifluoromethyl)phenyl)pyridine 1-oxideYield 34.5%

Reagents, catalysts & solvents 2

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 679Dimethyl SulfoxideSolvent

Conditions

Temperature
80 °C

Procedure

4-Chloropyridine-N-oxide (3.0 g, 23 mmol), 4-trifluoromethylphenylboronic acid (6.57 g, 34.6 mmol), K2CO3 (4.8 g, 35 mmol) and PdCl2(dppf) (470 mg, 0.57 mmol) were stirred in DMSO (40 mL) under vacuum for 30 min. The flask was flushed with nitrogen, and the mixture was heated to 80° C. for 10 min. Upon cooling, the mixture was diluted with methylene chloride and washed with 5% lithium chloride solution (5×), dried, concentrated, and the residue was purified by flash column chromatography (40 g ISCO column eluting with methylene chloride and a methanol/ammonia mixture (10:1); gradient 100% methylene chloride to 80% methylene chloride over 30 min at 40 mL/min) to provide the title compound (1.90 g, 34%) as a tan solid: ESI MS m/z 240 [M+H]+.

Workup

  1. customThe flask was flushed with nitrogen
  2. temperatureUpon cooling
  3. additionthe mixture was diluted with methylene chloride
  4. washwashed with 5% lithium chloride solution (5×)
  5. customdried
  6. concentrationconcentrated
  7. customthe residue was purified by flash column chromatography (40 g ISCO column
  8. washeluting with methylene chloride

Sources & evidence

ORD record
ord-6b7caa6a20df434196f81897f4ea5c1e
Source dataset
uspto-grants-2015_03
Patent number
US08993765B2

Reaction notes

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