Triethylamine → 5-Amino-7-chloro-3-(2,3,5'-tri-O-acetyl-beta-D-ribofuranosyl)-thiazolo[4,5-d]pyrimidin-2-one

Participants

Reaction Steps

To a solution of 25 (0.84 g, 1.90 mmol) in CHCl3 (9 mL) was added triethylamine (0.50 mL, 3.59 mmol) and POCl3 (1.60 mL, 17.1 mmol). After heating at reflux for 16 h, the reaction mixture was cooled to room temperature and poured onto ice and sat. aq. NaHCO3 (150 mL). The resulting mixture was extracted with CH2Cl2 (3×75 mL) and the combined organic layers dried (MgSO4). Concentration followed by flash chromatography (9:1/CH2Cl2:EtOAc) afforded 708 mg (87%) of product as a white solid, m.p. 101-103° C. 1H NMR (400 MHz, CDCl3) δ 6.10 (d, J=2.8 Hz, 1H), 6.01 (dd, J=5.6, 3.2 Hz, 1H), 5.92 (t, J=6.0 Hz, 1H), 5.42 (s, 2), 4.97 (dd, J=11.6, 3.6 Hz, 1H), 4.32 (m, 1), 4.21 (dd, J=12.0, 5.2 Hz, 1H), 2.12 (s, 6H), 2.06 (s, 3H).

Provenance & Evidence