Ethyl isocyanate → 7-Bromo-2-(3-ethyl-ureido)-[1,2,4]triazolo[1,5-a]pyridine-5-carboxylic acid ethyl ester

HRID 2112931Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[N:11]2[N:12]=[C:13]([NH2:15])[N:14]=[C:10]2[CH:9]=[C:8]([Br:16])[CH:7]=1)=[O:5])[CH3:2].[CH2:17]([N:19]=[C:20]=[O:21])[CH3:18]>C1COCC1.C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4]([C:6]1[N:11]2[N:12]=[C:13]([NH:15][C:20]([NH:19][CH2:17][CH3:18])=[O:21])[N:14]=[C:10]2[CH:9]=[C:8]([Br:16])[CH:7]=1)=[O:5])[CH3:2]

Participants

Conditions

Temperature: 100 °C

Procedure

2-Amino-7-bromo-[1,2,4]triazolo[1,5-a]pyridine-5-carboxylic acid ethyl ester (7) (760 mg, 2.66 mmol) was dissolved in THF/toluene (1:1, 40 mL), then ethyl isocyanate (1.89 g, 26.6 mmol) and a catalytic quantity of dibutyltindiacetate (10 drops) were added to the mixture. The reaction was then heated in a sealed tube at 100° C. for 15 h. This mixture was allowed to cool, then the solvents removed under reduced pressure to afford a solid which was purified by flash chromatography on silica 2% MeOH/CH2Cl2 as eluant) to give 7-bromo-2-(3-ethyl-ureido)-[1,2,4]triazolo[1,5-a]pyridine-5-carboxylic acid ethyl ester (8) LCMS (APCI+) 356, 358.

Workup

temperatureto cool
customthe solvents removed under reduced pressure
customto afford a solid which
customwas purified by flash chromatography on silica 2% MeOH/CH2Cl2 as eluant)

Sources & evidence

ORD record: ord-6be9ee39dfdb43d5899d1b9780a1d2e0
Source dataset: uspto-grants-2009_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07524860B2

Reaction notes

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