99295-21-3Relevant articles and documents
A Novel Three-Step Synthesis of a Pyrrolopyrimidine C-Nucleoside
Cupps, Thomas L.,Wise, Dean S.,Townsend, Leroy B.
, p. 1058 - 1064 (2007/10/02)
The phosphorus ylide, triphenylphosphorane (10) was synthesized in two steps from 6-(bromomethyl)-2,4-dimethoxy-5-nitropyrimidine (8).Compound 10 was condensed with 2,3-O-isopropylidene-5-O-(triphenylmethyl)-D-ribofuranose (1) to form the anomeric pair of protected homo-C-nucleosides, 2,4-dimethoxy-5-nitro-6-C-pyrimidine (11) and 2,4-dimethoxy-5-nitro-6-C-pyrimidine (12).Compound 10 also reacted with 2,3-O-isopropylidene-D-ribofuranose (6) to form the nontritylated compounds 2,4-dimethoxy-6-C--5-nitropyrimidines (14 and 15).Acid treatment of 11 or 12 afforded the deblocked homo-C-nucleoside 6-C--5-nitropyrimidine-2,4-dione (16), while reduction of 11 produced the 5-amino-pyrimidine homo-C-nucleoside 17 in quantitative yield. 6-(Cyanomethyl)-2,4-dimethoxy-5-nitropyrimidine (18) reacted with 2,3-O-isopropylidene-5-O-(triphenylmethyl)-D-ribofuranosyl chloride (19) to form the R and S diastereomers of 2-(2,4-dimethoxy-5-nitropyrimidin-6-yl)-2-(2,3-O-isopropylidene-5-O-(triphenylmethyl)-α-D-ribofuranosyl)acetonitrile (20a and 20b).The major component (20a) was reduced catalytically to the pyrrolopyrimidine 21.Under mild acid treatment 21 was deblocked to form 2,4-dimethoxy-7-C-(α-D-ribofuranosyl)pyrrolopyrimidine (22).Strong, aqueous acid treatment of 21 afforded a 1/1 mixture of 22 and the β anomer 23.
