2,3-Diaminopyridine → 8-Amino-3-(2-propynyl)-2-methylimidazo[1,2-a]pyridine
Reaktionsgleichung
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[CH:4][N:3]=1.S(O[CH:14]([CH2:18][C:19]#[CH:20])[C:15](=O)[CH3:16])(C)(=O)=O>CO>[NH2:8][C:7]1[C:2]2[N:3]([C:14]([CH2:18][C:19]#[CH:20])=[C:15]([CH3:16])[N:1]=2)[CH:4]=[CH:5][CH:6]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A mixture of 2,3-diaminopyridine (62.8 g) and 3-mesyloxy-5-hexyn-2-one (109.5 g) in methanol (126 ml) was refluxed for 20 hours. After methanol was evaporated in vacuo, sodium bicarbonate aqueous solution was added to the residue and then the mixture was extracted with ethyl acetate, washed with water and sodium chloride aqueous solution, and evaporated in vacuo. The resultant residue was subjected to column chromatography on silica gel (310 g) and eluted with a mixture of methylene chloride and acetonitrile. The eluates containing the object compound were combined and evaporated in vacuo. The residue was suspended in diethyl ether and the resultant precipitates were collected by filtration to give 8-amino-3-(2-propynyl)-2-methylimidazo[1,2-a]pyridine (18.42 g).