Purine diol

The reagent can, for instance, be employed on silica gel, kieselguhr. Si 50000, cellulose and NH2 layers the reaction is appreciably less sensitive on RP 18, CN and Diol phases, neither is there any color differentiation of the purine derivatives [8J. Cellulose and polyamide layers are not suitable, since the whole layer background is colored dark brown [8]. 

The synthesis of 9-(l,4-dihydroxybut-2-oxy)purines commenced with 2-butene-l,4-diol (1004) and via 1005 to 1006, which upon reaction with 1007 gave 1011 and then, upon hydrolysis, the racemic alkoxyamine 1012. The chiral derivatives commenced with the enantiomers of malic acid (1009) through 1010 to 1008, as shown in the scheme. Treatment of 1012 with 996 and further transformations followed almost the same sequence as before to give 1013. 

Chan, C. et al. (Glaxo Group Ltd) 2-(Purin-9-yl)-tetrahydrofuran-3-4-diol derivatives, WO 9941267, WO 9938877. 

Some heterocycles can be linked to supports as tetrahydropyranyl derivatives. Attachment of indoles, purines, or tetrazoles (Table 3.29) has been achieved by treatment of a support-bound dihydropyran with the heterocycle in the presence of catalytic amounts of pyridinium tosylate [487], camphorsulfonic acid [539], or TFA [540] in DCE at 60-80 °C for 16-24 h. Indole-derived orthoesters, such as that in Entry 7 (Table 3.29), can be prepared by heating the indole with triethyl orthoformate (160 °C, 24 h) followed by acid-catalyzed reaction of the resulting orthoester with a resin-bound diol [541,542], As illustrated by Entry 8 (Table 3.29), indoles can also be linked to the Wang resin or related supports as carbamates. Cleavage by TFA is, how-... 

LJ1251 (2R,3f ,4S)-2-(2-chloro-6-(3-iodobenzylamino)-9H-purin-9-yl) tetrahydrothiophene-3,4-diol... 

A 2- or 6-hydroxy-substituted purine can be prepared from the corresponding 4,5-diamino-pyrimidinol by cyclization with an acid, ester, ortho ester, or amide. If the ring closure is performed with reagents such as urea, alkyl chloroformates, urethanes, phosgene, and alkyl isocyanates, the 8-hydroxypurines are formed. Various xanthine and uric acid derivatives have been prepared by the condensation of 5,6-diaminopyrimidine-2,4-diols with formic acid. Purin-2-ol (1) was prepared by this route from 4,5-diaminopyrimidin-2-ol and ethyl orthoformate. ... 

PAHs are ubiquitous environmental pollutants known to be mutagenic and carcinogenic in mammalian cells [131, 132]. PAHs require metabolic activation that results in diol epoxide formation via reactions that are catalyzed by epoxide hydrolase and the CYP450 family of enzymes [133], Diol epoxides are highly reactive, particularly toward purines in DNA, forming guanine and adenine adducts that exist as as and trans stereoisomers [134]. Transcription past adducts derived from diol epoxides of benzo[o]pyrene (benzo[a]pyrene diol expoxide (B[a]PDE)), benzo[c]phenanthrene (benzo[c]phenanthrene diol epoxide (B[c]PhDE)), and dibenzo[a,l]pyrene (dibenzo[o,l]pyrene diol epoxide (B[a,l]PDE)) has been studied. 

This unusual annulation was reported with saxitoxin, 2,6-diamino-4- [(amino-carbonyl)oxy]methyl -3a,4,8,9-tetrahydro-l//,10/7-pyrrolo[l,2-c]-purine-10,10-diol (38a) isolated from tissue of a bullfrog and its derivatives, neosaxitoxin, 2,6-diamino-4- [(aminocarbonyl)oxy]methyl -3a,4,5,6,8,9-hexahydro-lf/,10//-pyr-rolo[l,2-c]purine-10,10-diol (38b) (91MI1)), gonyautoxin, 2,6-diamino-4- [(ami-nocarbonyl)oxy]methyl -3a,4,5,6,8,9-hexahydro-lf/,10/7-pyrrolo[l,2-c]purine-9,10, 10-triol (38c) (Scheme 9). Application of these compounds as local anaesthetics was published by Kohane (98MIP1). 

AI3-52268 CCRIS 994 3,7-Dihydro-1H-purine-2,6-dione 2,6-Dk)xo-1,2,3,5tetrahydropurine 2,5Dioxo-purine EINECS 200-718-6 EPA Pesflcide Chemical Code 116900 Isoxanthine NSC 14664 Pseudoxanthine Purine-2(3H),6(1H)-dione Purine-2,6-diol 1H-Purine-2,6-diol 9H-Purine-2,6-diol 1H-Purine-2,6-dione, 3,7-dihydro- 2,6(1,3)-Purinedion Purine-2,5(1H,3H)-dione 9H-Purine-2,5(1H,3H)-dione USAF CB-17 XAN Xanth-ic oxide Xanthin Xanthine. Used in organic synthesis and medicine. Yellowish powder soluble in H2O (0.007 g/100 ml at 25", 0.07 g/100 ml at 100"), less soluble in EtOH. Am. Bbrganics Dajac Labs. U.S. BioChem. 

---