o-Nitrophenyl-1,3-propanediol was covalently linked to long chain alkyl amine controlled pore glass (LCAA-CPG) beads through a stable phosphoramidate diester link. The resulting solid support was found suitable for the automated synthesis of 3 -phosphate unmodified as well as base-sensitive oligonucleotides. Efficient cleavage from the solid support was achieved by photolysis.