Efficient Synthesis of Antisense Phosphorothioate Oligonucleotides:  Evaluation of Dichloroacetic Acid at Higher Concentration to Reduce Cycle Time

Efficiency of phosphorothioate oligonucleotide syntheses could be improved by increasing the concentration of dichloroacetic acid in toluene to 10% from 3% (v/v) during the detritylation step. It was also found that dichloroacetic acid is better than dichloropropionic acid when compared at similar concentrations.