تفاعل #47759

معادلة التفاعل

25

5-Amino-3-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosyl)-3H-thiazolo[4,5-d]pyrimidin-2,7-dione

P2S5

→

77

المردود 90.0%

5-Amino-7-thioxo-3-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosyl)-thiazolo[4,5-d]pyrimidin-2-one

المردود 90.0%

المذيبات

pyridine

ظروف التفاعل

المعالجة

1. 1
   أخرىThe reaction mixture was evaporated to dryness in vacuo
2. 2
   workup.ADDITIONThe excess P2S5 was decomposed by the addition of H2O (40 mL) at 60° C
3. 3
   درجة الحرارةcooled to room temperature
4. 4
   استخلاصThe mixture was extracted with CHCl3 (3×40 mL)
5. 5
   تجفيفThe dried (MgSO4) organic layer
6. 6
   أخرىwas evaporated
7. 7
   أخرىto yield a syrup, which
8. 8
   أخرىwas purified by flash column chromatography (silica, acetone/CHCl3=15%)

الإجراء التجريبي

To a solution of 25 (1 g, 2.26 mmol) in pyridine (50 mL) was added at room temperature P2S5 (2.13 g, 4.79 mmol). The solution was refluxed gently (bath temperature 130-140° C.) for 29 h. The reaction mixture was evaporated to dryness in vacuo. The excess P2S5 was decomposed by the addition of H2O (40 mL) at 60° C. The mixture was stirred for 1 h at 60° C. and then cooled to room temperature. The mixture was extracted with CHCl3 (3×40 mL). The dried (MgSO4) organic layer was evaporated to yield a syrup, which was purified by flash column chromatography (silica, acetone/CHCl3=15%) to afford 0.93 g (90%) of 77 as a yellow solid: 1H (400 MHz, d6-DMSO) δ 12.50 (s, 1H), 7.35 (br s, 2H), 5.89 (m, 2H), 5.51 (t, J=6.4 Hz, 1H), 4.36 (dd, J=12.0, 4.0 Hz, 1H), 4.24 (m, 1H), 4.10 (q, J=6.0 Hz, 1H), 2.07 (s, 3H), 2.06 (s, 3H), 2.01 (s, 3H); MS (+)-ES [M+H]+ m/z 459.3.

المصدر