Ethanol → 9-(5-Carboxypentyl)-1,3-dimethylxanthine
Reaktionsgleichung
[C:1]([CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][NH:9][C:10]1[N:15]([CH3:16])[C:14](=[O:17])[N:13]([CH3:18])[C:12](=[O:19])[C:11]=1[NH:20][CH:21]=O)([OH:3])=[O:2].C(O)C>ClC1C=CC=CC=1Cl>[C:1]([CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][N:9]1[CH:21]=[N:20][C:11]2[C:12](=[O:19])[N:13]([CH3:18])[C:14](=[O:17])[N:15]([CH3:16])[C:10]1=2)([OH:3])=[O:2]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
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 5 N HCl. The precipitate was recrystalllized 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.