Triethylamine → 1-(2-deoxy-5-O-trityl-beta-D-threopentofuranosyl)thymine

Participants

Reaction Steps

In a 50-ml one-necked flask with lateral stopcock, 5′-O-tritylthymidine and triethylamine are placed in THF at t=0° C. under inert gas and stirring. Mesyl chloride is added dropwise from a syringe. The initially colorless solution becomes faintly yellow and cloudy. The reaction solution is allowed to warm up to room temperature within 30 minutes under stirring. Instead of the spot corresponding to starting material (Rf=0.29), a spot corresponding to the mesylated compound (Rf=0.45) is evident in TLC (V(MeOH):V(CH2Cl2)=1:19). At this point, 5 ml each of water, ethanol and 1 M sodium hydroxide solution are added to the reaction solution, which is stirred for 1 hour under reflux. In the TLC control test (V(MeOH):(VCH2Cl2)=1:19), exclusively the spot corresponding to the anhydro compound (Rf=0.15) is visible. Thereafter 3.4 ml of 10 M sodium hydroxide solution is added and the mixture stirred for 30 minutes under reflux. Two phases can form during this step. Instead of a spot corresponding to the anhydro compound (Rf=0.15), the product spot (Rf=0.33) is now evident on the TLC plate (V(MeOH):V(CH2Cl2)=1:19). The reaction solution is mixed with about 6 g of silica gel 60, and the solvent mixture is distilled off in the rotary evaporator. Subsequent column chromatography under flash conditions (silica gel 60; Ø=2.9 cm; h=32 cm; V(MeOH):V(CH2Cl2)=1:19+0.1% of triethylamine; 8.5 ml/min) yields the product, 1-(5-O-trityl-2-deoxy-β-D-lyxofuranosyl)thymine.

Provenance & Evidence