ChemInform Abstract: SYNTHESE VON 7‐(BETA‐D‐RIBOFURANOSYL)‐4‐METHYLMERCAPTO‐IMIDAZO(4,5‐D)‐V‐TRIAZIN

Synthesis of the sulfonyl analog of hypoxanthine, imidazo [4,5-e]-1,2,4-thiadiazine 1,1-dioxide

“…pH 8 with NaHC03, and extracted with CH2C12. The CH2C12 extracts were combined, dried (Na2S04), evaporated to dryness, and chromatographed on silica gel (1:1 petroleum ether/ethyl acetate) to yield the tribenzoyl derivative of 9c, 3.21 g (84%), as colorless crystals: mp 124-126 °C; NMR 11.32 (s, 1, exch NH), 8.11-7.89 (m, 8, C(3)H, C(6)H, and C6H5), 7.60-7.32 (m, 9, C6H6's), 6.34 (d, 1 ,J = 4.3 Hz, C(l)'H), A solution of 1.36 g (2.2 mmol) of 7-(2',3',5'-tri-0-benzoyl-/3-D-ribofuranosyl)imidazo[4,5-e]-l,2,4-thiadiazine 1,1-dioxide in 150 mL of methanolic ammonia was allowed to react at 20 °C for 2 days, was evaporated to about 15 mL, and was added to 150 mL of CH2C12 to precipitate the ammonium salt of 9c; 0.50 g (75%). The salt was converted to 9c by percolating a CH3OH solution of the product over a column containing Bio-Rad AG-50 (H+) and eluting with MeOH.…”

2‐Azapurine Nucleosides: Synthesis, Properties, and Base Pairing of Oligonucleotides

“…The first glycosylation reaction was described by Ofitserov and co-workers [36]. They treated 6-(methylsulfanyl)-2-azapurine (63) However, the N(7)-regioisomer 69 was isolated as major product in low yield (10%).…”