N-bromobutanimide → HCID 69651329, compound

Participants

Reaction Steps

NBS (1.42 g, 8.0 mmol, dissolved in 4 ml of dried DMF) is added, at room temperature, to a solution of 2'-deoxytubercidin (1.0 g, 4.0 mmol) and NaOAc (0.78 g, 8.0 mmol) in dried DMF (10 ml). The red solution is stirred for 10 minutes and then evaporated. Title compound (38) is obtained as colorless crystals (400 mg, 25%) following flash chromatography (column: 20×5 cm, CH2Cl2 /MeOH, 9:1), evaporation of the more rapidly migrating zone and subsequent recrystallization from isopropanol. Isolation of the more slowly migrating zone yields 5-bromo-2'-deoxytubercidin (130 mg, 10%). Method B: a solution of NBS (1.42 g, 8.0 mmol, dissolved in 4 ml of dried DMF) is added to a solution of 5-bromo-2'-deoxytubercidin (1.3 g, 4.0 mmol) and NaOAc (0.785 g, 8.0 mmol) in dried DMF (10 ml). Purification, see method A. Yield: 490 mg, 30% of 21. Melting point: 181° C. TLC (silica gel, CH2Cl2 /MeOH, 9:1): Rf 0.40. 1H-NMR (D6 -DMSO): δ=2.12 (m, Hα -2'); 2.50 (m, Hβ -2'); 3.51 (m, 2H, H-5'); 3.84 (m, 1H, H-4'); 4.44 (m, 1H, H-3'); 5.20, (br, 2H, 5'-OH, 3'-OH); 6.42 ("t", J=6.2 Hz, 1H, H-1'); 6.93 (br, 2H, NH2); 8.10 (s, 1H, H-2).

Provenance & Evidence