Patent ID: 6670468
Filing Date: 2003-12-30
Classification: C07H

Abstract:
A process for preparing a compound of the formula (Ia) in whichA is a radical of the formula â€”C(H)(R3)â€”N(R1)(R2), in which R1 and R2 are independently of each other, H, C1-C10 alkyl, a radical of the formula II â€”(CH2â€”CH2â€”X)mâ€”R5â€ƒâ€ƒ(II), in which each X is, in each case independently of each other, O or N(R6), R5 and R6 mono-C1-C10 alkylamino-C2-C10 alkyl or N,N-di-C1-C10 alkylamino-C2-C10 alkyl, and m is an integer from 1 up to and including 3, amino-C3-C10 alkyl, N-mono-C1-C10 alkylamino-C3-C10-alkyl, or N,N-di-C1-C10 alkylamino-C3-C10 alkyl; or in which â€”N(R1)( R2) are together a radical of the formula (III), in which Y is O, S, SO, SO2 or N(R7), and R7 is H or â€”CH3; R3 is H, â€”CH3, â€”CH2â€”CH3, â€”CH2OH or â€”CH2â€”Oâ€”C1-C4 alkyl; or A is a radical of the formula (IVa) or (IVb) in which R, independently, has the meaning of R1 or R2, and U is O or CH2; Bâ€² is the radical of a nucleic acid base; and Va and Wa are, independently of each other, â€”OH, â€”NH2 or identically or differently protected hydroxyl or amino groups, wherein nucleosidic building blocks having, in the radical A, two heteroatoms linked to the same carbon atom are excluded,and wherein other reactive groups are present in the protected or unprotected state;wherein said process comprises reacting(a) a compound of the formula (A) in which Va and Wa are, independently of each other, a protected hydroxyl or amino group, and Bâ€² is defined as above, with exocyclic amino groups in Bâ€² being protected by protecting groups, with a compound of the formula (B) Xâ€”CH2â€”Aâ€ƒâ€ƒ(B) in which X is Cl, Br, I, tosyl-O or mesyl-O, and A is defined as above, with primary and secondary amino groups and primary hydroxyl groups in A being protected by protecting groups; or (b) a compound of the formula (D) with a compound of theformula (F) NH(R1) (R2)â€ƒâ€ƒ(F) wherein functional groups in R1, R2 are protected and L is a leaving group; or (c) a compound of the formula (D) with an azide and subsequently reducing to provide a compound of the formula (G)