A simplified procedure for synthesizing nucleoside 1-thiotriphosphates: dATP alpha S, dGTP alpha S, UTP alpha S, and dTTP alpha S.

A procedure for synthesizing a nucleoside 1-thiotriphosphate in a single reaction vessel beginning with the nucleoside, PSCl3, and PPi is described. Reaction of the dried nucleoside with PSCl3 in anhydrous triethylphosphate is followed by addition of the tetrabutylammonium salt of PPi. Addition of excess triethylamine precipitates the nucleotides. The crude product is dissolved in water, and the nucleoside 1-thiotriphosphate is purified in 24% to 50% yield by chromatography. The method is applied to the synthesis of dATP alpha S, dGTP alpha S, UTP alpha S and dTTP alpha S.