Process for preparing dithiophosphate oligonucleotide analogs via nucleoside thiophosphoramidite intermediates
Patent 5218088 Issued on June 8, 1993. Estimated Expiration Date: June 8, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A method for synthesis of oligonucleotide analogs having dithiophosphate internucleosidic linkages is described. Monohalohydrocarbylthiophosphoramidites are utilized to prepare nucleoside thiophosphoramidite intermediates which are activated for nucleoside coupling with tetrazole catalysts. Sulfur oxidation and dehydrocarbylation of the coupled thiophosphite intermediates provide oligonucleotide analogs having achiral dithiophosphate internucleosidic linkages.
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