Реакция #417915

Уравнение реакции

N2

9-(2-O-benzyl-β-D-arabinofuranosyl)-6-[2-(trimethylsilyl)ethoxy]-9H-purine

4,4′-dimethoxytrityl chloride

→

product

Выход 44.4%

9-{5-O-[bis(4-methoxyphenyl)(phenyl)methyl]-2-O-benzyl-β-D-arabinofuranosyl}-6-[2-(trimethylsilyl)ethoxy]-9H-purine

Выход 44.4%

Растворители

EtOAc

hexane

triethylamine

EtOAc

hexane

pyridine

dichloromethane

Условия реакции

Обработка

1. 1
   Другоеquenched with 100 mL saturated NaHCO3 solution
2. 2
   ЭкстракцияAfter the aqueous layer was extracted with dichloromethane (100 mL) three times
3. 3
   Другоеevaporated
4. 4
   ДругоеThe residue was purified by flash chromatography (gradient

Методика

Under the protection of N2, to a solution of 9-(2-O-benzyl-β-D-arabinofuranosyl)-6-[2-(trimethylsilyl)ethoxy]-9H-purine (1.60 g, 3.49 mmol) in 20 mL pyridine was added 4,4′-dimethoxytrityl chloride (2.13 g, 6.28 mmol). The mixture was stirred at room temperature for 2 h. The reaction was diluted with 100 mL dichloromethane and quenched with 100 mL saturated NaHCO3 solution. After the aqueous layer was extracted with dichloromethane (100 mL) three times, the organic layers were combined and evaporated. The residue was purified by flash chromatography (gradient: hexane with EtOAc 0-100%, with 1% triethylamine in both hexane and EtOAc) to produce 1.18 g (1.55 mmol, 44.4%) product. LCMS: for C43H48N4O7Si calculated 760.9. found 762.5 [M+H]+. 1H NMR (600 MHz, CD3CN) δ: 8.39 (s, 1H), 8.10 (s, 1H), 7.42-7.40 (m, 2H), 7.29-7.13 (m, 10H), 6.86-6.85 (m, 2H), 6.81-6.77 (m, 4H), 6.50 (d, J=5.5 Hz, 1H), 4.69-4.65 (m, 2H), 4.49-4.45 (m, 2H), 4.24-4.21 (m, 2H), 4.02 (m, 1H), 3.8 (dd, 10.4, 6.3 Hz, 1H), 3.29 (dd, J=10.4, 3.5 Hz, 1H), 1.22 (m, 2H), 0.09 (s, 1H). 13C NMR (600 MHz, CD3CN) δ: 160.82, 152.01, 142.44, 130.24, 130.21, 128.39, 128.25, 128.01, 127.86, 127.61, 127.05, 113.21, 83.56, 82.87, 82.37, 74.31, 72.54, 65.26, 63.56, 55.10, 17.27, −2.13.

Источник