Pj. Dudfield et al., Synthesis of C-ribosyl 1,2,4-triazolo[3,4-f][1,2,4]triazines as inhibitorsof adenosine and AMP deaminases, J CHEM S P1, (20), 1999, pp. 2937-2942
Modified C-nucleosides and nucleotides with an enhanced tendency to undergo
covalent hydration are of interest as potential inhibitors of adenosine de
aminase (ADA) and AMP deaminase, respectively. In a search for such compoun
ds we have synthesized 6-dimethylamino-3-(beta-D-ribofuranosyl)-1,2,4-triaz
olo[3,4-f][1,2,4]triazine 4 in four steps (42% overall yield) from the read
ily available allonic acid 6 and the hydrazine 7. The hydrazide 16 derived
from 6 and 7 (78%) is converted directly into the cyclised chloro compound
19 (62%) with phosphorus trichloride oxide, followed by dechlorination (96%
) and deprotection (90%). Riboside 4 undergoes partial hydration in water t
o the covalent hydrate 22, and is a modest inhibitor of mammalian ADA (IC50
180 mu M).