Traube, Wilhelm

The first of the 8-azapurines, 1,3-dimethyl-8-azapurin-2,6-dione (1), was made at the start of this century by Wilhelm Traube, who cyclized the corresponding 4,5-diaminopyrimidine with nitrous acid. Similar syntheses from pyrimidines, although excluding any possibility of placing an alkyl substituent in the 7 or 8 position, dominated the field until 1968 when appropriately substituted triazoles were introduced to overcome these limitations. These two approaches to the preparation of 8-azapurines, from pyrimidines or from triazoles, are expanded in Sections IV,A and B, respectively. 

The first correct synthesis of caffeine was achieved by Wilhelm Traube (1866-1942) in 1900. [519] In spite of some modifications that were introduced over the years, Traube s procedure stUl serves today as the basis for the industrial synthesis of caffeine, theobromine and theophyUine. 

Among the many colloidal materials he studied was copper-ferrocyanide, which is formed as a gelatinous precipitate when copper sulfate is mixed with K ferrocyanide. The semipermeable properties of a membrane made of copper-ferrocyanide gel was discovered by Moritz Traube, who proposed the atomic sieve theory to explain semipermeability. Osmotic studies of Wilhelm Pfeifer provided the foundation for van t HofTs law of osmosis ... 

These (except those for guanine and adenine) are the same as the formulae proposed by Medicus (see p. 778), Fischer s colleague in Wurzburg. Fischer synthesised theobromine, and in 1898 purine, the basic substance of the whole series.2 Parabanic, oxaluric, and barbituric acids were synthesised by Pono-mareff and by Grimaux. Important syntheses in the group were also carried out by Wilhelm Traube, assistant professor in Berlin. ... 

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