Cesium carbonate → Tert-butyl 2-(pyridin-3-yl)-[1,2,4]triazolo[1,5-a]pyridin-6-ylcarbamate

HRID 588420Notes

Reaction equation

HRID 588420 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([N:8]=[C:9]([C:11]3[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=3)[N:10]=2)[CH:7]=1.[C:17](=[O:24])([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])[NH2:18].C(=O)([O-])[O-].[Cs+].[Cs+].C1(P(C2C=CC=CC=2)C2C3OC4C(=CC=CC=4P(C4C=CC=CC=4)C4C=CC=CC=4)C(C)(C)C=3C=CC=2)C=CC=CC=1>O1CCOCC1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[C:20]([O:19][C:17](=[O:24])[NH:18][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([N:8]=[C:9]([C:11]3[CH:12]=[N:13][CH:14]=[CH:15][CH:16]=3)[N:10]=2)[CH:7]=1)([CH3:23])([CH3:22])[CH3:21]

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 77922tert-Butyl carbamateHCID 6360441,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine)HCID 717439846-Bromo-2-(pyridin-3-YL)-[1,2,4]triazolo[1,5-A]pyridine

Product 1

HCID 89464387Tert-butyl 2-(pyridin-3-yl)-[1,2,4]triazolo[1,5-a]pyridin-6-ylcarbamateYield 72.5%

Reagents, catalysts & solvents 2

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 312751,4-DioxaneSolvent

Procedure

A mixture of 6-bromo-2-(pyridin-3-yl)-[1,2,4]triazolo[1,5-a]pyridine (1.65 g, 6.00 mmol), tert-butyl carbamate (843 mg, 7.2 mmol) and cesium carbonate (2.74 g, 8.4 mmol) in 1,4-dioxane (37.8 ml) was purged with argon. Then tris(dibenzylideneacetone)dipalladium(0) (330 mg, 360 μmol) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (416 mg, 720 μmol) were added and the purging was repeated. The mixture was heated to reflux and stirred for 18 hours under argon atmosphere. After evaporation to dryness under reduced pressure, the crude material was purified by flash chromatography (50 g silicagel column using heptane/ethyl acetate 20-100% as eluent). Final evaporation of the solvents afforded (2-pyridin-3-yl-[1,2,4]triazolo[1,5-a]pyridin-6-yl)-carbamic acid tert-butyl ester (1.35 g, 72.5%) as yellow solid. Mp.: 296° C. MS: m/z=312.3 (M+H+).

Workup

  1. customwas purged with argon
  2. temperatureThe mixture was heated
  3. temperatureto reflux
  4. customAfter evaporation to dryness under reduced pressure
  5. customthe crude material was purified by flash chromatography (50 g silicagel column using heptane/ethyl acetate 20-100% as eluent)
  6. customFinal evaporation of the solvents

Sources & evidence

ORD record
ord-4f093fc78e5e46c8befeab98410224a8
Source dataset
uspto-grants-2016_01
Patent number
US09227970B2

Reaction notes

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