반응 #76250

반응 방정식

TMSOTf

argon lead

TMSOTf

32

5-(2-Phtalimidoethyl)uracil

33

ribose tetrabenzoate

→

34

수율 86.0%

1-(2, 3, 4-Tri-O-benzoyl-β-D-ribopyranosyl)-5-(2-phtalimidoethyl)uracil

수율 86.0%

용매

AcOEt

AcOEt n-heptane

Et2O

acetonitrile

반응 조건

후처리

1. 1
   workup.ADDITIONa further 7 ml (28 mmol) of BSA were then added by means of syringe
2. 2
   workup.WAITAfter one hour
3. 3
   온도Subsequently, the reaction mixture was heated to 50° C
4. 4
   workup.STIRRINGAfter stirring at 50° C. for 2.5 h (TLC checking)
5. 5
   온도the mixture was cooled to RT
6. 6
   추출NaHCO3 solution and intensively extracted
7. 7
   workup.STIRRINGby stirring for 10 min
8. 8
   세척It was again washed with 100 ml of NaHCO3 solution
9. 9
   추출the aqueous phases were again extracted with 100 ml of AcOEt
10. 10
    기타phases were dried
11. 11
    기타the solvents were removed in vacuo in a rotary evaporator
12. 12
    기타After drying in an oil pump vacuum
13. 13
    기타20.9 g of crude product were obtained
14. 14
    기타Chromatography on silica gel (h=25 cm, f=5 cm, AcOEt/n-heptane 1:1) yielded a TLC-uniform, foamy product, which
15. 15
    여과Filtration
16. 16
    기타drying in an oil pump vacuum

실험 절차

7.00 g (24 mmol) of 32 and 13.6 g (24 mmol) of 33 were suspended in 120 ml of acetonitrile in a 250 ml three-necked flask, equipped with an argon lead-in, internal thermometer and septum. Firstly 12.2 ml (50 mmol) of BSA and, after stirring for 30 min, a further 7 ml (28 mmol) of BSA were then added by means of syringe. After heating to 40° C. for a short time, the reaction mixture clarified. 13 ml (72 mmol) of TMSOTf were added by means of syringe at room temp. After one hour, no product formation was yet observed (TLC checking, AcOEt/n-heptane 1:1). A further 13 ml (72 mmol) of TMSOTf were therefore added. Subsequently, the reaction mixture was heated to 50° C. After stirring at 50° C. for 2.5 h (TLC checking), the mixture was cooled to RT., [lacuna] onto an ice-cold mixture of 250 ml of AcOEt and 190 ml of satd. NaHCO3 solution and intensively extracted by stirring for 10 min. It was again washed with 100 ml of NaHCO3 solution and the aqueous phases were again extracted with 100 ml of AcOEt. The dil. org. phases were dried using MgSO4 and the solvents were removed in vacuo in a rotary evaporator. After drying in an oil pump vacuum, 20.9 g of crude product were obtained. Chromatography on silica gel (h=25 cm, f=5 cm, AcOEt/n-heptane 1:1) yielded a TLC-uniform, foamy product, which was digested using Et2O. Filtration and drying in an oil pump vacuum afforded 15 g (86%) of 34.

출처