The preparation of a disulfide-tethered precipitative soluble support and its use for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3'-(2-chlorophenylphosphate) building blocks is described. To obtain the building blocks, N-acyl protected 2'-deoxy-5'-O-(4,4'-dimethoxytrityl)ribonucleosides were phosphorylated with bis(benzotriazol-1-yl) 2-chlorophenyl phosphate. The "outdated" phosphotriester strategy, based on coupling of P-V building blocks in conjunction with quantitative precipitation of the oligodeoxyribonucleotide with MeOH is applied. Subsequent release of the resulting phosphate and base-protected oligodeoxyribonucleotide trimer 3'-pTpdC^BzpdG^ibu-5' as its 3'-(2-chlorophenyl phosphate) was achieved by reductive cleavage of the disulfide bond.