CYCLIZATION OF SOME 8-SUBSTITUTED 5'-CHLORO-5'-DEOXY ADENOSINES
ZARINA D. E., LIEPINS E. E., LIDAKS M. J.
Institute of Organic Synthesis, Academy of Sciences of the Latvian SSR, Riga
Abstract: Three 8-R-substituted adenosines (R=OCH3, NH2, SH) were chlorinated with thionyl chloride in hexamethylphoshoric triamide (HMPA) solution. The chlorination of the first derivative was accompanied by demethylation, the product, upon heating in DMF being transformed into 3,5'-cyclo-8-hydroxyadenosine. The other two adenosines showed a remarkable trend to form 5',8-cycloadenosines under chlorination conditions. As 1H NMR data show, 5'-chloro-5'-deoxy-8-mercaptoadenosine is able to form a 5',8- as well as 3,5'-cycle. Synthesis of 8-amino-5'-deoxy-5'-S-isobutylthioadenosine from 8-amino-5'-chloro-5'-deoxyadenosine confirmed the latter's structure. The above compounds showed moderate cytotoxicity against melanoma B 16 cells in vitro.
Russian Journal of Bioorganic Chemistry 1990, 16 (1):83-89