Imidazole → HCID 15747244, compound

Participants

Reaction Steps

A mixture of 5′-O-phthalimidothymidine (8.54 g, 22 mmol), t-butyldiphenylsilylchloride (6.9 ml, 26.5 mmol), imidazole (3.9 g, 57.3 mmol) and dry DMF (130 ml) was stirred at room temperature for 16 h under argon. The reaction mixture was poured into ice-water (600 ml) and the solution was extracted with CH2Cl2 (2×400 ml). The organic layer was washed with water (2×250 ml) and dried (MgSO4). The CH2Cl2 layer was concentrated to furnish a gummy residue which on purification by silica gel chromatography (eluted with EtOAc:Hexanes; 1:1, v/v) furnished 12.65 g (92%) of 3′-O-(t-butyldiphenylsilyl)-5′-O-phthalimidothymidine as crystalline material (mp 172-173.5° C.). 1H NMR (DMSO-d6) δ 11.31 (s, 1, NH), 7.83 (m, 4, ArH), 7.59 (m, 4, TBDPhH), 7.51 (s, 1, C6H), 7.37-7.45 (m, 6, TBDPhH), 6.30 (dd, 1, H1′, J1′,2′=8.8 Hz, J1′,2″=5.6 Hz), 4.55 (m, 1, H4′), 4.15 (m, 1, H3′) 3.94-4.04 (m, 2, H5′,5″), 2.06-2.13 (m, 2, H2′,2″), 1.97 (s, 3, CH3), 1.03 (s, 9, C(CH3)3). Anal. Calcd. for C34H35O7N3Si: C, 65.26; H, 5.64; N, 6.71. Found: C, 65.00; H, 5.60; N, 6.42.

Provenance & Evidence