Purine

• 7H- imidazo ( 4,5-d ) pyrimidine
• 3,5,7 - Triazaindol
• Abbreviation R ( purine )

Colorless needles

Fixed

1.22 g · cm -3

217 ° C.

• Soluble in water and hot ethanol
• Insoluble in diethyl ether and chloroform

800 mg · kg -1 ( LD50, rat, ip)

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Purine ( R) is a heterobicyclic aromatic organic compound having four nitrogen atoms. Purine is the base body of the substance group of purines.

• 3.1 purine alkaloids

Representation and extraction

The unsubstituted purine does not occur in nature. The first representation Emil Fischer succeeded in 1884 by the heating of uric acid. It is prepared by the reaction of amino acetonitrile with formamide or in modified form from Phthalimidoacetonitril and Trisformaminomethan. Another production is possible in a based on Wilhelm Traube synthesis of 4,5- Diamino and anhydrous formic acid.

Properties

Physical Properties

Purine forms colorless crystals which melt at 217 ° C. It crystallizes in a rhombic crystal lattice. For fixed connection a combustion enthalpy of -2708 kJ · mol -1 was determined. The corresponding enthalpy of formation is 169.4 kJ · mol -1.

Chemical Properties

The molecule may be considered as a fused ring system, composed of both heterocycles pyrimidine (red) and imidazole ( green). Why is his systematic name 7H -imidazol [ 4,5-d ] pyrimidine.

The 7H- purine stands with its isomer, the 9H- purine, in a tautomeric equilibrium.

Derived compounds

Purine alkaloids

From the basic structure of the xanthine also some alkaloids are derived from the purine alkaloids: