Mesitylene sulfonyl-3-nitro-triazole

Protection of Phosphates and Phosphonates. 2-Hydroxy ethyl phenyl sulfone (1) has been used to differentially protect phosphate esters for nucleotide synthesis. Thus, reaction of the diphosphate (8) with 1 and l-(mesitylene-2-sulfonyl)-3-nitro 1,2,4-trIazole (MSNT) in pyridine afforded the differentially protected phosphate 9 in very good yield (eq 5). The 2-phenylsulfonylethyl phosphate can be cleaved under mild conditions by treatment with triethylamine. 

Synthesis of 01igodeo iQrribonucleotides by the Phosphotriester Method. l-(Mesitylene-2-sulfonyl)-3-nitro-l,2,4-triazole-(MSNT) has been widely used as a condensing agent for the synthesis of oligodeoxynucleotides by the phosphotriester method. ... 

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