Water → 7236-57-9

1-(2-deoxy-beta-D-ribofuranosyl)-5-methyl-2-pyrimidinone (beta-deoxyribosyl-5-methyl-2-pyrimidinone). 4-thiothymidine was prepared by a published procedure (Wempen, et al., in Grossmen, L., and Moldare, K. (Eds.), Methods in Enzymology, Academic Press, XII, Part A, 75, 1967). Deoxyribosyl-5-methyl-2-pyrimidinone was prepared from the 4-thiothymidine by reduction with Raney nickel. 5.9 gm (22 mmole) of 4-thiothymidine was added to 180 ml of distilled water and 60 ml of ethyl alcohol in a flask with a reflux condenser. 24 gm of Raney nickel was added and the solution heated to reflux. For the highest yields a 4-thiothymidine solution was triturated with each Raney nickel preparation and the optical density of a sample in 0.1 N HCl was determined at 260, 322, and 334 nanometers. The optical density decreased at all three wave lengths. The reaction was terminated when the optical density at 322 nanometers was equal to or greater than the optical density at 334 nanometers. The decrease in optical density at 334 nanometers from the initial solution was about a factor of 6 for the maxim yield. The reaction was followed with silica gel thin layer chromatography (TLC) using isopropanol. A blue fluorescent spot, characteristic of the compound, appeared with an Rf of 0.35. The initial greenish solution became a very light yellow by the end of the reaction. Because other products where formed the reaction was not run until all of the 4-thiothymidine was used. The suspension was filtered hot and the Raney nickel boiled with 150 ml of water. The solution was filtered hot. The combined filtrates were evaporated. Deoxyribosyl-5-methyl-2-pyrimidinone was purified by dry column chromatography with Woelm silica III. 10 ml of methanol was added to the solid from the Raney nickel reduction. 3.7 ml of the clear solution was added to 3.7 gm of Woelm silica III and air dried. The dried silica with the deoxyribosyl-5-methyl-2-pyrimidinone was added to the top of a column of dry Woelm silica, 20 inches long by 1 inch diameter, contained in nylon tubing. Isopropanol was the solvent. The solvent front was allowed to reach the bottom of the silica column before terminating the chromatography. The nylon tubing was cut into 1 inch sections and the silica in each section was extracted with 10 ml of methanol. Samples from each section were run on silica gel TLC with isopropanol. The methanol extracts were pooled from those sections that showed only the fluorescent spot with Rf 0.35 . The pooled silica from the appropriate sections was extracted again with methanol and pooled with the first extraction. After filtration the methanol was evaporated to a small volume and the remaining fine particles of silica were removed by centrifugation. The remaining methanol was evaporated and the residue dissolved in 10 ml of hot ethyl alcohol. The solution was placed at -20° C. Crystals formed overnight. The yellow supernatant was decanted and the crystals washed in cold ethanol. The volume was reduced to 4 ml and placed at -20° C. More crystals formed. Silica gel TLC revealed a contamination of less than 5%. The ultraviolet-visible spectrum of a solution of the crystals was equivalent to the literature spectrum (Laland, et al., Biochemical Journal, 90:76, 1964). The overall yield from 4-thiothymidine to the final product was about 25%.

1. temperaturethe solution heated to reflux

ORD record

ord-62e0c88f9ce84b908a1a8b7540493fef

Source dataset

uspto-grants-1992_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05126439