Synthesis of carbon-3-substituted 1,5,9-triazacyclododecanes, RNA cleavage agents suitable for oligonucleotide tethering.

Two derivatives of 1,5,9-triazacyclododecane bearing an alkylamino tether group at carbon-3 (7 and 13) were synthesized. The first of them, 7, was prepared starting from diethyl 2-(2-cyanoethyl)malonate and the second one, 13, from glycerol. In both cases, the cyclization reaction was performed by allowing the corresponding ditosylates (5 and 12) to react with TBD. The guanidinium salts formed were reduced in situ to the orthoamides (6 and 12), acid-catalyzed hydrolysis of which yielded the title compounds. The suitability of the azacrowns prepared for oligonucleotide tethering is also demonstrated.