反应 #3524530
相关文献 (1)
openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US08642756B2
反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: Uridine (15, 100.0 g, 409.5 mmol) was co-evaporated to dryness with anhydrous pyridine (600 mL) and re-suspended in anhydrous pyridine (700 mL). To this stirred fine suspension was added 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane (135.7 g, 482.5 mmol) over 60 min at ambient temperature. After stirring the fine suspension for 17 h at ambient temperature, the reaction was quenched by adding methanol (20 mL) and then concentrated under reduced pressure. The residue was partitioned between ethyl acetate (1.5 L) and water (2 L). The organic layer was further washed with 5% hydrochloric acid (2×1 L), brine (500 mL), dried over solid sodium sulfate (50 g), filtered and concentrated under reduced pressure to the crude product, ca 250 g. The residue was subjected to a filtration column using silica gel (1.75 kg) and a gradient of ethyl acetate in hexanes 20-65%. The pure product fractions as judged by a homogenous TLC (Rf 0.55 in 1:1 hexanes-ethyl acetate) were combined and concentrated under reduced pressure and dried (40° C., 0.2 mm Hg, 24 h) to afford 145.5 g (76%) of 16 as a white foam solid. An additional fraction (35 g) of slightly impure 16 was also collected. 1H NMR (DMSO-d6) δ (ppm) 11.35 (s, 1H, NH), 7.66 (d, 1H, J=7.6 Hz, H-6), 5.57 (d, 1H, J=4.8 Hz, 2′-OH), 5.50-5.49 (m, 2H, 1′-H and H-5), 4.14-4.18 (m, 3H, 2′,3′,4′-H), 3.97-3.87 (m, 2H, 5′-Ha and Hb), 1.02-0.95 (m, 28H, CH(CH3)2). the reaction was quenched by adding methanol (20 mL) concentrated under reduced pressure The residue was partitioned between ethyl acetate (1.5 L) and water (2 L) The organic layer was further washed with 5% hydrochloric acid (2×1 L), brine (500 mL) dried over solid sodium sulfate (50 g) filtered concentrated under reduced pressure to the crude product, ca 250 g The residue was subjected to a filtration column concentrated under reduced pressure dried (40° C., 0.2 mm Hg, 24 h)
来源 ID: ord-33ed4ab25b724539beadd53c911dcf21