| abstract |
Novel N-4 modified pyrimidine analogs are provided having the structure (I) or (II) <IMAGE> (I) <IMAGE> (II) wherein: R1 is selected from the group consisting of hydrogen, acid-sensitive, base-stable blocking groups and acyl capping groups; R2 is lower alkyl; R3 is C1-C12 alkylene containing 0 to 6 linkages selected from the group consisting of -0-, -S- and -NH-; R4 is <IMAGE> in which R9 is hydrogen or an optionally substituted aliphatic group; R10 and R11 are hydrocarbyl or together form a mono- or polyheterocyclic ring; R5 is hydrogen or lower alkyl; R6 is selected from the group consisting of hydrogen, methyl, bromo and iodo; R7 is C1-C12 alkylene containing 0 to 6 linkages selected from the group consisting of -O-, -S- and -NR12- wherein R12 is hydrogen or lower alkyl; and R8 is a protecting group that can be removed and replaced by reduction. Synthetic methods for preparing the compounds are provided as well, as are methods for making and using polynucleotide probes containing the novel pyrimidine analogs. |