2,5-Dimethoxytetrahydrofuran → HCID 14962900, compound

Participants

Reaction Steps

To stirred acetic acid (1.5 L) at 80° C. was added over a 5-minute period a mixture of methyl 4-amino-2-propylimidazol-5-carboxylate (Example 4, 145 g, 0.798 mol) and sodium acetate (388 g, 4.73 mol). The mixture was heated at reflux for 5 minutes and then 2,5-dimethoxy-tetrahydrofuran (117 g, 0.885 mol) added all at once. The resulting dark solution was refluxed for 20 minutes, then poured onto ice. The gummy mixture was extracted with dichloromethane, the combined organic layers washed with water and dried over anhydrous magnesium sulfate. The filtrate was concentrated under reduced pressure and the residue dissolved in dichloromethane (2 L). The dichloromethane solution was treated with silica gel (500 g) and the suspension filtered through a bed of silica gel (300 g) eluting with dichloromethane. The filtrate was evaporated to dryness under reduced pressure and the crude product recrystallized from ether/hexane (2:1) to provide 86 g (46% yield) methyl 2-propyl-4-(1H-pyrrol-1-yl)imidazol-5-carboxylate, mp 135°-138° C. MS (DEI) 234 (M+1).

Provenance & Evidence