Ethanol → 9-(5-Carboxypentyl)-1,3-dimethylxanthine

Participants

Reaction Steps

9.3 Grams (0.03 mol) of the formamido derivative (IV) was suspended in 500 ml of o-dichlorobenzene and stirred at reflux under an inert atmosphere for 4 hours. It was cooled and the solvent removed on a rotary evaporator attached to a vacuum pump. The crystalline residue was partitioned between 200 ml of ether and 100 ml of 5% aqueous sodium bicarbonate solution. The aqueous phase was separated, washed with 100 ml of ether, and acidified to pH 3.2 with 5N HCl. The precipitate was recrystallized first from aqueous methanol, then from absolute ethanol to give 5.8 g (66% yield) of the xanthine (V) as fine white crystals, mp 177° C.

Provenance & Evidence