Ethyl isocyanate → N-(7-Bromo[1,2,4]triazolo[1,5-a]pyridin-2-yl)-N′-ethylurea

Participants

Reaction Conditions

Reaction Steps

7-Bromo-[1,2,4]triazolo[1,5-a]pyridin-2-ylamine (compound 3, 1.22 g, 5.73 mmol) was dissolved in THF/toluene (1:1, 60 mL), then ethyl isocyanate (4.07 g, 57.3 mmol) and a catalytic quantity of dibutyltindiacetate (6 drops) were added to the mixture. The reaction was then heated in a sealed tube at 100° C. for 24 h. This mixture was allowed to cool, then the solvents removed under reduced pressure to afford an oily solid, which was triturated with Et2O, giving a solid which was collected by filtration. Further material was isolated by flash chromatography of the resulting filtrate on silica (2% MeOH/CH2Cl2 as eluant) to give compound 1-(7-bromo-[1,2,4]triazolo[1,5-a]pyridin-2-yl)-3-ethyl-urea (4) LCMS (APCI+) 284, 286.

Provenance & Evidence