1636. Caffeine

Nomenclature

CAS number: 58-08-2
3,7-Dihydro-1,3,7-trimethyl-1H-purine-2,6-dione; 1,3,7-trimethylxanthine; 1,3,7-trimethyl-2,6-dioxopurine; coffeine; thein; guaranine; methyltheobromine; No-Doz (BMS).
C8H10N4O2; mol wt 194.19.
C 49.48%, H 5.19%, N 28.85%, O 16.48%.

Description and references

Naturally occurring alkaloid commonly found in tea leaves, coffee beans, cocoa beans, maté leaves, guarana paste and kola nuts. Originally isolated from coffee in 1821. Synthesis: E. Fischer, Ber. 15, 453 (1882); E. Fischer, L. Ach, ibid. 28, 3135 (1895); W. Traube, ibid. 33, 1371, 3035 (1900); H. Bredereck et al., ibid. 83, 201 (1950). Crystal structure: D. J. Sutor, Acta Crystallogr. 11, 453 (1958). Arrhythmogenic effects in humans: D. J. Dobmeyer et al., N. Engl. J. Med. 308, 814 (1983). Teratogenicity study: P. E. Palm et al., Toxicol. Appl. Pharmacol. 44, 1 (1978). HPLC determn in serum: D. T. Holland et al., J. Chromatogr. B 707, 105 (1998). Comprehensive description: M. U. Zubair et al., Anal. Profiles Drug Subs. 15, 71-150 (1986). Review of dietary sources: D. M. Graham, Nutr. Rev. 36, 97-102 (1978); of clinical pharmacology: N. L. Benowitz, Annu. Rev. Med. 41, 277-288 (1990); of CNS effects: A. Nehlig et al., Brain Res. Rev. 17, 139-170 (1992); of therapeutic uses: J. Sawynok, Drugs 49, 37-50 (1996).

Chemical structure

Properties

Hexagonal prisms by sublimation, mp 238°. Odorless with bitter taste. Sublimes 178°. Fast sublimation is obtained at 160-165° under 1 mm press. at 5 mm distance. d418 1.23. pH of 1% soln 6.9. Absorption spectrum: Hartley, J. Chem. Soc. 87, 1802 (1905). One gram dissolves in 46 ml water, 5.5 ml water at 80°, 1.5 ml boiling water, 66 ml alcohol, 22 ml alcohol at 60°, 50 ml acetone, 5.5 ml chloroform, 530 ml ether, 100 ml benzene, 22 ml boiling benzene. Freely sol in pyrrole; in tetrahydrofuran contg about 4% water; also sol in ethyl acetate; slightly in petr ether. Soly in water is increased by alkali benzoates, cinnamates, citrates or salicylates. LD50 orally in mice, hamsters, rats, rabbits (mg/kg): 127, 230, 355, 246 (males); 137, 249, 247, 224 (females) (Palm).

Derivative

Monohydrate.

Properties

Felted needles, contg 8.5% H2O. Efflorescent in air; complete dehydration takes place at 80°.

Derivative

Mixture with citric acid.

Nomenclature

CAS number: 69-22-7
Caffeine citrate; citrated caffeine; Cafcit (Roxane).

Description and references

Clinical trial in treatment of apnea in premature neonates: P. B. Larsen et al., Acta Paediatr. 84, 360 (1995).

Properties

White, crystalline powder; acid reaction. Sol in about 4 parts warm water.

Therapeutic Category

CNS stimulant; respiratory stimulant.

Therapeutic Category (Veterinary)

Cardiac and respiratory stimulant; diuretic.

Keywords

CNS Stimulant