Synthesis of Purine-6-carboxaldehyde and Related Derivatives¹

Abstract

The double wave tended to disappear with increasing water concentration, and at intermediate peroxide concentrations it was either absent or the first wave was very poorly developed as the water concentration approached 30% of the total volume. The reason for the double wave was unclear, but it appeared likely that slow diffusion of the reduction products from the region of the dropping electrode may have been responsible since even vigorous mixing for several seconds was often insufficient to prevent layering when additions were made to the glycol solutions. In fact, a fairly persistent "streamer" due to the passage of the mercury droplet through the solutions could be visualized by adding a small amount of a dye to the more concentrated glycol solutions. A rotating microelectrode might have been superior to the dropping electrode in the media used.

Applications of Purine Ring Opening in the Synthesis of Imidazole, Pyrimidine, and New Purine Derivatives

“…The latter can be thermally cleaved in aqueous ammonia, producing diaminopyrimidine 284. [216] Similar pyrimido-pyrimidines have been obtained from purin-6-ylpyridinium chlorides in aqueous solutions using an analogous photoinduced hydrolytic imidazole ring opening and cycloisomerization sequence. [217,218] There has also been research on formamide use for purine nucleoside degradation in DNA sequencing.…”

Oxidation of Carbon–Halogen Bonds

“…There appear to be no examples of the oxidation of secondary halides to ketones by this method, presumably for reasons of lower reactivity. (25) Br ii, NaOH, 60%~C There is an interesting limitation to the method: 4-nitrobenzyl chloride gives only 1% of the aldehyde, the major product being the result of single-electron transfer and radical coupling (equation 21).42 A PdQ catalyst has been used in situ to isomerize a secondary allylic halide prior to oxidation (equation 22).…”

Darstellung und Eigenschaften einiger 6‐ und 2.6‐substituierter Purine

“…auch I. c. 21,22)) ergab Purinaldehyd-(6) 23), das starke Xanthin-Oxydase-Hemmung zeigt 24). Die Knoevenugel-Kondensation von 6-Methyl-purin wurde von Hanzpton25) durchgefuhrt.…”

“…Der Aldehyd wurde katalytisch zum 6-Hydroxymethyl-purin (15) hydriert und die entsprechende Carbonsaure (13) 23,47) durch Oxydation von 15 oder 10 mit KMn04 dargestellt.…”

“…Tub.) : Der Aldehyd wird ahnlich umgesetzt, wie fruher fiir Purin-aldehyd-(6) beschrieben23). Bei sechs verschiedenen Ansatzen der Umsetzung von N-:2-Amino-pirrinyl-(6J -methyl j-pyridiniumjodid mit p -Nitroso-dimerhylunilin erhielt man ausschliefllich das entsprechende Nitron; Versuche, das Anil zu isolieren, verliefen erfolglos.Umsetzungen von 2-Amiuo-purin-uldehyd-(6j-thiosemicurbuzon mit Hydrazin a) 2-Amino-purin-aldehyd-(6)-hydruzon: 2.34 g (10 mMol) des Thiosemicurbuzons wurden in 60 ccm 20proz.…”