Cesium carbonate → Ethyl 7-(tert-butoxycarbonylamino)-[1,2,4]triazolo[1,5-a]pyridine-2-carboxylate

HRID 1802191Notes

Reaction equation

Br[C:2]1[CH:7]=[CH:6][N:5]2[N:8]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[N:10]=[C:4]2[CH:3]=1.[C:16](=[O:23])([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])[NH2:17].C(=O)([O-])[O-].[Cs+].[Cs+]>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].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>[C:19]([O:18][C:16]([NH:17][C:2]1[CH:7]=[CH:6][N:5]2[N:8]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[N:10]=[C:4]2[CH:3]=1)=[O:23])([CH3:22])([CH3:21])[CH3:20]

Participants

Conditions

Temperature: 110 °C

Procedure

To an argon purged solution of ethyl 7-bromo-[1,2,4]triazolo[1,5-a]pyridine-2-carboxylate (1.76 g, 6.52 mmol) in dioxane (45 ml) are added tert-butyl carbamate (916 mg, 7.82 mmol), tris(dibenzylideneacetone)dipalladium(0) (119 mg, 130 μmol), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (151 mg, 261 μmol) and cesium carbonate (2.97 g, 9.12 mmol). The resulting mixture is heated to 110° C. and stirred for 20 hours. The reaction mixture is loaded on silica and purified by flash chromatography on a 50 g silica column using heptane/ethyl acetate 30-100% as eluent affording ethyl 7-(tert-butoxycarbonylamino)-[1,2,4]triazolo[1,5-a]pyridine-2-carboxylate (1.07 g, 54%) as a light yellow solid. mp.: 220-2° C. MS: m/z=307.3 (M+H+).

Workup

custompurified by flash chromatography on a 50 g silica column

Sources & evidence

ORD record: ord-fe6877d43fc44c05ad8401c364c73a58
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08349824B2

Reaction notes

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