Patent ID: 8093397

Claim:
A composition of matter for use in condensation reactions in the preparation of oligonucleotides comprising acetonitrile and an activator comprising an N-alkylimidazole and a 1,1-dioxo-1,2-dihydro-1λ 6 -benzo[d]isothiazol-3-one represented by the following structural formula: wherein: p is 0 or an integer from 1 to 4; X 7 is O or S; and R for each occurrence is a substituent selected from the group consisting of halo groups, aliphatic groups, —NR 11 R 12 , —OR 13 , —OC(O)R 13 , —C(O)OR 13 , cyano, aryl groups, heterocyclyl groups, —CHO, —COR 13 , —NHCOR 13 , aralkyl groups, and —SR 13 ; or two adjacent R groups taken together with the carbon atoms to which they are attached form a six membered saturated or unsaturated ring; wherein: R 11 and R 12 are each, independently, —H, an aliphatic group, an aryl group, an aralkyl group; or together with the nitrogen to which they are attached form a 5 or 6-membered heterocyclic ring ; and R 13 is an aliphatic group, an aryl group, or an aralkyl group.