Pyridine → HCID 178430605, compound

0.15 g (0.31 mmol) of 5'-tritylamino-5'-deoxy-thymidine [prepared as described in step (a) above] was dried by azeotropic distillation with pyridine and then dissolved in 2 ml of methylene chloride. 0.23 ml (1.2 mmol) of N,N-diisopropyl-N-ethylamine was then added to the resulting solution, after which 0.08 ml (0.36 mmol) of 2-cyanoethyl N,N-diisopropylchlorophosphoramidite was added over a period of 2 minutes in a stream of nitrogen. The resulting mixture was then stirred at room temperature for 60 minutes. At the end of this time, it was confirmed that the starting compound had disappeared by thin layer chromatography, and the reaction mixture was diluted with 30 ml of ethyl acetate. The resulting organic solution was washed with a saturated aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order. The organic layer was through a 1PS (trade mark) filter paper (Whatman), and the filtrate was freed from the solvent by distillation under reduced pressure. The resulting residue was purified by column chromatography through 15 g of silica gel (70-230 mesh), using ethyl acetate as the eluent, to give 0.19 g (yield 89%) of the title compound as a foamy substance.

1. washThe resulting organic solution was washed with a saturated aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order
2. filtrationfilter paper (Whatman)
3. distillationthe filtrate was freed from the solvent by distillation under reduced pressure
4. customThe resulting residue was purified by column chromatography through 15 g of silica gel (70-230 mesh)

ORD record

ord-7b0a35c21d9e43f285b8b54a52921274

Source dataset

uspto-grants-1998_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05807837