Cytidine, 4'-C-(chloromethyl)-2'-deoxy-3'-O-[(1,1-dimethylethyl)dimethylsilyl]-5'-O-[(1,1-dimethylethyl)diphenylsilyl]-2'-fluoro- synthesis

Yield:1445379-90-7 78.8%

Reaction Conditions:

Stage #1: C₃₂H₄₄ClFN₂O₅Si₂with dmap;Triphenylsilyl chloride;triethylamine in acetonitrile at 20; for 14 h;
Stage #2: with ammonia in tetrahydrofuran;acetonitrile at 20; for 2 h;

Steps:

7 Preparation of (P7-2):

P7-1 (0.80 g, 1.3 mmol), DMAP (0.3 g, 2.6 mmol), TPSCl (0.8 g, 2.6 mmol) and Et₃N (0.3 g, 2.6 mmol) were dissolved in MeCN (30 mL). The mixture was stirred at R.T. for 14 hours. NH₃ in THF (saturated at 0° C., 100 mL) was added to the mixture, and the mixture was stirred at R.T. for 2 hours. The solvent was removed, and the residue was purified by column (DCM/MeOH=100:1 to 50:1) to give P7-2 (0.63 g, 78.8%) as a white solid.

References:

US2013/165400,2013,A1 Location in patent:Paragraph 0287; 0288