N-bromobutanimide → 4-(8-Ethylimidazo[1,2-a]pyridin-3-yl)-2-(methylthio)pyrimidine-5-carbonitrile

Participants

Reaction Steps

4.89 g of 4-[(Z)-2-ethoxyvinyl]-2-(methylthio)-5-pyrimidinecarbonitrile (synthesized according to the method disclosed in International Publication WO2006/025567, page 90 to 91) was dissolved in a mixed solvent of 50 mL of 1,4-dioxane and 5 mL of water, then 3.93 g of N-bromosuccinimide was added under an ice-cold condition, and the mixture was stirred for 1 hour at room temperature. To the reaction solution was added 2.7 g of 3-ethylpyridine-2-amine (synthesized according to the method disclosed in International Publication WO2006/025567, page 142), and the solution was stirred overnight at room temperature. To the reaction solution was added a saturated aqueous solution of sodium hydrogen carbonate, the solution was extracted with chloroform, and the resulting organic layer was dried over anhydrous sodium sulfate. The insolubles were filtered, and the filtrate was concentrated under reduced pressure. Diethylether was added to the resulting residue, and the resultant solution was stirred for 3 hours. Thus produced solid was taken by filtration and dried under reduced pressure to obtain 4.46 g of 4-(8-ethylimidazo[1,2-a]pyridin-3-yl)-2-(methylthio)pyrimidine-5-carbonitrile [5-6] (hereinafter, referred to as the compound [5-6]) as a pale yellow solid.

Provenance & Evidence