Patent ID: 8889860

Claim:
A compound of the formula: wherein: R 1 is hydroxy, monophosphate, diphosphate, triphosphate, α-thiotriphosphate or polyphosphate; R 2 is hydrogen or hydroxy; R 3 is alkyl (C≦8) or substituted alkyl (C≦8) ; R 4 is hydrogen, hydroxy, halo, amino, nitro, cyano, azido or mercapto; alkyl (C≦6) , acyl (C≦6) , alkoxy (C≦6) , acyloxy (C≦6) , alkylamino (C≦6) , dialkyl-amino (C≦6) , amido (C≦6) , or a substituted version of any of these groups; R 5 and R 6 are each independently: hydrogen, hydroxy, halo, amino, nitro, cyano, azido or mercapto; alkyl (C≦6) , alkenyl (C≦6) , alkynyl (C≦6) , aryl (C≦6) , aralkyl (C≦8) , heteroaryl (C≦6) , acyl (C≦6) , alkoxy (C≦6) , acyloxy (C≦6) , alkylamino (C≦6) , dialkyl-amino (C≦6) , amido (C≦6) , or a substituted version of any of these groups; a group of formula: wherein X is —O—, —S—, or —NH—; or alkanediyl (C≦12) , alkenediyl (C≦12) , alkynediyl (C≦12) , or a substituted version of any of these groups; Y is —O—, —NH—, alkanediyl (C≦12) or substituted alkane-diyl (C≦12) ; n is an integer from 0-6; and m is an integer from 0-6; or a -linker-reporter; or a salt, tautomer, or optical isomer thereof.