74706-79-9

Upstream product

• 104-30-3 2-(4-nitrophenyl)ethyl acetate 
• 53676-18-9 2,5-dichlorophenyl phosphorodichloridate 
• 69395-15-9 2-(2-chloro-4-nitro-phenyl)-ethanol 
• 42926-80-7 5'-O-(4-monomethoxytrityl)-2'-deoxythymidine 
• 103-45-7 acetic acid phenethyl ester 

Downstream Products

• 74712-88-2 C₅₄H₆₃ClN₅O₁₅PSi 
• 74712-86-0 Phosphoric acid 2-(2-chloro-4-nitro-phenyl)-ethyl ester (2R,3S,5R)-2-[(4-methoxy-phenyl)-diphenyl-methoxymethyl]-5-(5-methyl-2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-tetrahydro-furan-3-yl ester; compound with triethyl-amine 

Relevant academic research and scientific papers

Nucleotide. XIV. Substituierte β-Phenylaethyl-Gruppen. Neue Schutzgruppen fuer Oligonucleotid-Synthesen nach dem Phosphorsaeuretriester-Verfahren

Various o- and p-substituted β-phenylethanols (2-10) have been synthesized and investigated as blocking groups in the phosphotriester approach.A large number of 5'-O-tritylated thymidine-3'-phosphotriesters (13-36) with two different phosphate protecting groups have been prepared, characterized, and studied according to their chemical stability and usefullness for oligonucleotide syntheses.The combination of a 5'-O-monomethoxytrityl- and a 3'-(2,5-dichlorophenyl, p-nitrophenylethyl)-phosphate function as in 18 turned out to possess optimal properties as a monomeric nucleotide building block due to the fact that these blocking groups can be quantitatively and selectively be removed without harming each other by trifluoroacetic acid in chloroform to 41, by oximate to 42, and by DBU to 43.The base-catalyzed removal of the monosubstituted phenylethyl groups by DBU or DBN respectively as well as the disubstituted phenylethyl groups by triethylamine in aprotic solvents is a β-elimination process leading to phosphodiesters without attack on the P-center.

New improvements in oligonucleotide synthesis by use of the p-nitrophenylethyl phosphate blocking group and its deprotection by DBU or DBN

Phosphate protection in the phosphotriester approach is improved by the new, versatile p-nitrophenylethyl group due to its stability in the condensation step and its clean removal by DBU and DBN respectively.