A simple and efficient procedure for the synthesis of 5′-aminoalkyl oligodeoxynucleotides

Synthetic deoxyoligonucleotides have been 5'-aminoalkylated at the end of step-wise synthesis on the polymer support. This was achieved through the activation of the 5'-hydroxyl group as its 5'-imidazolyl derivative using carbonyldiimidazole, which was subsequently displaced with hexamethylene diamine to yield the title compound. The alkyl carbamate linkage thus generated withstands the deprotection conditions used in oligonucleotide synthesis. Purification by gel electrophoresis and further derivatization at the 5'-amino group with N-hydroxysuccinimidobiotin is described.