Cytidine → Cytarabine

5 G of cytidine are dissolved in 50 ml of acetic acid. 4.75 ml of silicon tetrachloride are added to the solution. The mixture is stirred at 60° to 70°C for 20 minutes. Then, the mixture is refluxed for 3 hours under heating. The reaction mixture is concentrated under reduced pressure. The residue is dissolved in ice-water, and the aqueous solution is adjusted to pH 12.5 with an aqueous 2 N-sodium hydroxide solution. After the aqueous solution is stirred at room temperature for 30 minutes, said solution is passed through a column of 200 ml of a strong acidic ion exchange resin (H+ -form) (Diaion SK-IB). The column is washed with water and eluted with 1300 ml of aqueous 1N-ammonia. The eluate is concentrated under reduced pressure. The residue thus obtained is crystallized with ethanol and then recrystallized from 50 % ethanol. 2.7 G of 1-β-D-arabinofuranosyl cytosine are thereby obtained. Yield: 55 % M.p. 213°-214°C (decomp.)

1. temperatureThen, the mixture is refluxed for 3 hours
2. temperatureunder heating
3. concentrationThe reaction mixture is concentrated under reduced pressure
4. dissolutionThe residue is dissolved in ice-water
5. stirringAfter the aqueous solution is stirred at room temperature for 30 minutes
6. washThe column is washed with water
7. washeluted with 1300 ml of aqueous 1N-ammonia
8. concentrationThe eluate is concentrated under reduced pressure
9. customThe residue thus obtained
10. customis crystallized with ethanol
11. customrecrystallized from 50 % ethanol

ORD record

ord-8e612eee33fb435e9f954285a1df759e

Source dataset

uspto-grants-1976_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03950325