Process for the preparation of 2'-O-alkyl purine phosphoramidites
AssigneeIsis Pharmaceuticals, Inc.
InventorsPhillip Dan Cook, Daniel Peter Claude McGee, Charles John Guinosso
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Abstract
Processes for preparing 2'-O-alkylated guanosine, uridine, cytidine, and 2,6-diaminopurine 3'-O-phosphoramidites include the steps of alkylating nucleoside precursors, adding suitable blocking groups and phosphitylating. For the guanosine 2'-O-alkylated 3'-O-phosphoramidites, alkylation is effected on 2,6-diamino-9-(.beta.-D-ribofuranosyl)purine followed by deamination. For uridine 2'-O-alkylated 3'-O-phosphoramidites, alkylation is effect on a dialkyl stannylene derivative of uridine. For cytidine 2'-O-alkylated 3'-O-phosphoramidites, alkylation is effected directly on cytidine. Alkylation is effected directly upon 2,6-diaminopurine.
Claims25
A process for preparing an oligonucleotide that comprises at least one 2'-O-alkylated guanosine nucleotide comprising:
- alkylating a 2,6-diamino-9-(ribofuranosyl)purine to form a 2,6-diamino-9-(2'-O-alkylated ribofuranosyl)purine;
- deaminating said 2,6-diamino-9-(2'-O-alkylated ribofuranosyl)purine to form a 2'-O-alkylated guanosine;
- blocking the 5'-hydroxyl moiety of said 2'-O-alkylated guanosine;
- phosphitylating the 3'-position of said 5'-blocked 2'-O-alkylated guanosine to form a 2'-O-alkylated guanosine 3'-O-phosphoramidite;
- and
- coupling said 2'-O-alkylated guanosine 3'-O-phosphoramidite with a 5'-hydroxyl moiety on an oligonucleotide utilizing phosphoramidite coupling conditions.
A process for preparing an oligonucleotide that comprises at least one 2'-O-alkylated uridine nucleotide comprising:
- treating uridine with a dialkyltin oxide to form a 2',3'-O-dialkylstannylene derivative of uridine;
- alkylating said stannylene derivative of uridine to provide a 2'-O-alkylated uridine;
- blocking the 5'-hydroxyl moiety of said 2'-O-alkylated uridine;
- phosphitylating the 3'-position of said 5'-blocked 2'-O-alkylated uridine to form a 2'-O-alkylated uridine 3'-O-phosphoramidite;
- and
- coupling said 2'-O-alkylated uridine 3'-O-phosphoramidite to a 5'-hydroxyl moiety on an oligonucleotide utilizing phosphoramidite coupling conditions.
A process for preparing an oligonucleotide that comprises at least one 2'-O-alkylated 2,6-diamino-9-(.beta.-D-ribofuranosyl)purine nucleotide within the sequence of the oligonucleotide comprising:
- alkylating a 2,6-diamino-9-(.beta.-D-ribofuranosyl)purine to provide a 2'-O-alkylated 2,6-diamino-9-(.beta.-D-ribofuranosyl)purine;
- blocking the 5'-hydroxyl moiety of said 2'-O-alkylated 2,6-diamino-9-(8-D-ribofuranosyl)purine;
- phosphitylating the 3'-position of said 5'-blocked 2'-O-alkylated 2,6-diamino-9-(.beta.-D-ribofuranosyl)purine to form a 2'-O-alkylated 2,6-diamino-9-(.beta.-D-ribofuranosyl)purine 3'-O-phosphoramidite;
- and
- coupling said 2'-O-alkylated 2,6-diamino-9-(.beta.-D-ribofuranosyl)purine 3'-O-phosphoramidite to a 5'-hydroxyl moiety on an oligonucleotide utilizing phosphoramidite chemistry.
A process for preparing a 2'-O-alkylated uridine 3'-O-phosphoramidite comprising the steps of:
- treating a uridine with a dialkyltin oxide to form a 2',3'-O-dialkylstannylene derivative of uridine;
- alkylating said stannylene derivative of uridine to form a 2'-O-alkylated uridine;
- blocking the 5'-hydroxyl moiety of said 2'-O-alkylated uridine;
- and
- phosphitylating the 3'-position of said 5'-blocked 2'-O-alkylated uridine.
Dependencies are inferred from the claim text.