Synthesis and single‐crystal X‐ray diffraction analysis of 2‐sulfamoyladenosine (6‐amino‐9‐β‐D‐ribofuranosylpurine‐2‐sulfonamide)

2‐Amino‐9‐β‐D‐ribofuranosylpurine‐2‐sulfonamide (2‐sulfamoyladenosine, 4 ), a congener of sulfonosine ( 3 ), was synthesized by four different routes. Acid catalyzed fusion of 6‐chloropurine‐2‐sulfonyl fluoride ( 5 ) with 1,2,3,5‐tetra‐ O ‐acetyl‐β‐D‐ribofuranose ( 8 ) gave a good yield of 6‐chloro‐9‐(2,3,5‐tri‐ O ‐acetyl‐β‐D‐ribofuranosyl)purine‐2‐sulfonyl fluoride ( 9 ). Ammonolysis of 9 furnished 4 . Lewis acid catalyzed glycosylation of the trimethylsilyl derivative of either 6‐chloropurine‐2‐sulfonamide ( 6 ) or 6‐aminopurine‐2‐sulfonamide ( 7 ) with 8 gave the corresponding N 9‐glycosylated products, 10 and 11 , respectively, which on ammonolysis gave 4 . Amination of 2‐thioadenosine ( 12 ) with chloramine solution gave the sulfenamide derivative 13 , which on subsequent oxidation with m ‐chloroperoxybenzoic acid furnished an alternate route to 4 . The structure of 4 was established by single‐crystal X‐ray diffraction studies. 2‐Sulfamoyladenosine ( 4 ) is devoid of significant inhibitory activity against L1210 leukemia in mice.