反应详情

The crystals of 1-(2-chloroethyl)-3-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl) urea (3.0 g) obtained in step (1) above were partially dissolved in methanol (100 ml) and to the resulting suspension was added an 0.2 N methanolic solution of sodium methoxide (8 ml). Dissolution of the crystals in the methanol was completed by stirring the mixture at room temperature for 10 minutes. The resulting solution was stored in the cold for 7 days and then treated with 2 ml of a cation exchange resin "Amberlite" IR-120 (H+ form) (Amberlite is a trademark of Rohm and Haas Co.) to remove the sodium cation. The cation exchange resin was filtered off and the filtrate was concentrated in vacuo. The resulting residue was dissolved in water (100 ml) and washed three times with ethyl ether (50 ml each). The aqueous layer was concentrated in vacuo and the residue was crystallized from methanol to give 1-(2-chloroethyl)-3-(β-D-ribofuranosyl) urea (1.06 g) as crystals. Yield 81%.

1. customcold for 7 days
2. additiontreated with 2 ml of a cation exchange resin "Amberlite" IR-120 (H+ form) (Amberlite
3. custom) to remove the sodium cation
4. filtrationThe cation exchange resin was filtered off
5. concentrationthe filtrate was concentrated in vacuo
6. dissolutionThe resulting residue was dissolved in water (100 ml)
7. washwashed three times with ethyl ether (50 ml each)
8. concentrationThe aqueous layer was concentrated in vacuo
9. customthe residue was crystallized from methanol