Hydrochloric Acid → 1-(3-Hydroxy-3-methyl-4-pentynyl)-3-methyl-7-propylxanthine

Participants

Reaction Conditions

Reaction Steps

A solution of 55.7 g (0.2 mol) of 3-methyl-1-(3-oxobutyl)-7-propylxanthine in a mixture of 200 ml each of dioxane and toluene was added dropwise in 45 minutes to a stirred suspension of 36.8 g (0.4 mol) of lithium acetylide as ethylenediamine complex and 98.6 g (0.4 mol) of anhydrous cerium(III) chloride in a mixture of 500 ml each of dry dioxane and toluene at 50° C. The mixture was then stirred at 50° C. for 7 hours, cooled and, after addition of cold water and acidification with 2 N hydrochloric acid, intensively extracted with chloroform, the extract was washed with water, dried over sodium sulfate and evaporated under reduced pressure, and the residue was purified by filtration through a silica gel column in the eluent chloroform/methanol (50:1), resulting in 35.0 g (58% of theory) of solid, which was recrystallized from ethanol with large losses.

Provenance & Evidence