反应详情

A solution of (S)-2-(4-chlorophenyl)-α-methyl-3H-imidazo[4,5-b]pyridine-3-acetic acid (3.0 g, 0.00995 mole) and concentrated sulfuric acid (4 drops) in ethylene glycol (50 ml) was refluxed under nitrogen for three hours, and then poured into a saturated sodium bicarbonate solution (200 ml). Water (50 ml) was added and the product was extracted into two portions of ethyl acetate. The combined organic layers were washed twice with water and once with a saturated sodium chloride solution, dried over magnesium sulfate, treated with charcoal and filtered. Evaporation of the solvents under reduced pressure gave 1.9 g (56% yield) of solid which was dissolved in hot isopropyl ether (with a little isopropyl alcohol added). The solution was stirred and cooled to room temperature to precipitate a solid. The mixture was cooled in the freezer, the solid was collected by filtration, rinsed with isopropyl ether and dried under high vacuum at room temperature overnight to give 1.44 g of title compound, mp 112°-113.5° C.

1. extractionthe product was extracted into two portions of ethyl acetate
2. washThe combined organic layers were washed twice with water and once with a saturated sodium chloride solution
3. dry with materialdried over magnesium sulfate
4. additiontreated with charcoal
5. filtrationfiltered
6. customEvaporation of the solvents under reduced pressure