Microwave-assisted rapid deprotection of oligodeoxyribonucleotides

A novel method for the deprotection of oligodeoxyribonucleotides under microwave irradiation has been developed. The oligodeoxynucleotides having base labile, phenoxyacetyl (pac), protection for exocyclic amino functions were fully deprotected in 0. 2 M sodium hydroxide (methanol:water : : 1:1, v/v) = A and 1 M sodium hydroxide (methanol:water : : 1:1, v/v) = B using microwaves in 4 and 2 min, respectively. The deprotection of oligodeoxyribonucleotides carrying conventional protecting groups, dAbz, dCbzand dGpac, for exocyclic amino functions was achieved in 4 min in B without any side product formation. The deprotected oligonucleotides were compared with the oligomers deprotected using standard deprotection conditions (29% aq. ammonia, 16 h, 55 degrees C) with respect to their retention time on HPLC and biological activity.