10059. Xanthine

Nomenclature

CAS number: 69-89-6
3,7-Dihydro-1H-purine-2,6-dione; 2,6(1H,3H)-purinedione; 2,6-dioxopurine.
C5H4N4O2; mol wt 152.11.
C 39.48%, H 2.65%, N 36.83%, O 21.04%.

Description and references

Occurs in animal organs, yeast, potatoes, coffee beans, tea. First isolated from urinary bladder stones: Beilstein 26, 447 (1937). Prepd by treating a sulfuric acid soln of guanine with sodium nitrite: Fischer, Ann. 215, 309 (1882). Several other syntheses, cf. Levene, Bass, Nucleic Acids (New York, 1931).

Chemical structure

Properties

Scales, plates from water. Dec on heating without melting and with partial sublimation. Kb at 40° = 6.09×1014; Ka at 40° = 1.19×1010. Absorption spectrum: Kalckar, J. Biol. Chem. 167, 429 (1947). One gram dissolves in 14.5 liters of water at 16°, in 1.4 liters boiling water; less sol in alcohol. Sol in mineral acids, freely sol in NH4OH and in NaOH solns.

Derivative

1,3-Dimethylxanthine see Theophylline.

Derivative

3,7-Dimethylxanthine see Theobromine.

Derivative

1,3,7-Trimethylxanthine see Caffeine.