5-(Ethylthio)-1H-tetrazole is used a powerful activator in DNA and RNA syntheses.
5-(Ethylthio)-1H-Tetrazole is prepared from the corresponding alkyl thiocyanate and sodium azide through a [2?+?3] cycloaddition under phase transfer catalytic conditions (eq 1). The ratio of the solvent (water to toluene) as well as the reaction temperature are important factors in obtaining preparative yields of the alkylthiotetrazoles. 5-Ethylthio-1H-tetrazole has also been prepared using DMF as solvent albeit in much lower yield.
5-(Ethylthio)-1H-tetrazole (ETT) is an efficient activator, that activates nucleoside phosphoramidites towards condensation with a nucleoside to form dinucleoside phosphates during oligonucleotide synthesis.
recrystallized from toluene.