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

HRID 1844438Notes

Reaction equation

HRID 1844438 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-1aa488c9687c46d7beb7d8e895ead745
Source dataset
uspto-grants-2015_02
Patent number
US08946427B2

Reaction notes

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