SYNTHESIS OF OLIGONUCLEOTIDES

摘要

A method for preparing an oligonucleotide comprising the steps of a) providing a hydroxyl containing compound having the formula (A), wherein B is a heterocyclic base and i) R₂ is H, a protected 2'-hydroxyl group, F, a protected amino group, an O-alkyl group, an O-substituted alkyl, a substituted alkylamino or a C4 '-O2 ' methylen linkage; R₃ is OR'₃, NHR"₃, NR"₃R'₃, wherein R₃ is a hydroxyl protecting group, a protected nucleotide or a protected oligonucleotide, R"₃, R"₃ are independently amine protecting groups, and R₅ is OH or ii) R₂ is H, a protected 2'-hydroxyl group, F, a protected amino group, an O-alkyl group, an O-substituted alkyl, a substituted alkylamino or a C4'-O2 'methylen linkage; R₃ is OH and R₅ is OR'₅ and R'₅ is a hydroxyl protecting group, a protected nucleotide or a protected oligonucleotide or iii) R₂ is OH, R₃ is OR'₃, NHR"₃, NR"₃R'"₃, wherein R₃ is a hydroxyl protecting group, a protected nucleotide or a protected oligonucleotide, R"₃, R"₃ are independently amine protecting groups, and R₅ is OR'₅ and R'₅ is a hydroxyl protecting group, a protected nucleotide or a protected oligonucleotide b) reacting said compound with a phosphitylating agent in the presence of an activator having the formula (I) (activator I) wherein R = alkyl, cycloalkyl, aryl, aralkyl, heteroalkyl, heteroaryl; R₁, R₂ = either H or form a 5 to 6-membered ring together; X₁, X₂ = independently either N or CH; Y = H or Si(R₄)₃, with R₄= alkyl, cycloalkyl, aryl, aralkyl, heteroalkyl, heteroaryl; B = deprotonated acid to prepare a phosphitylated compound; c) reacting said phosphitylated compound without isolation with a second compound having the formula (A) wherein R₅, R₃, R₂, B are independently selected, but have the same definition as above in the presence of an activator II different from activator I.