Targeting Ligands For Therapeutic Compounds
Described are novel targeting ligands that may be linked to compounds, such therapeutic compounds, that are useful in directing the compounds to the target in vivo. The targeting ligands disclosed herein can serve to target expression-inhibiting oligomeric compounds, such as RNAi agents, to liver cells to modulate gene expression. The targeting ligands disclosed herein, when conjugated to an expression-inhibiting oligomeric compound, may be used in a variety of applications, including use in therapeutic, diagnostic, target validation, and genomic discovery applications. Compositions including the targeting ligands disclosed herein when linked to expression-inhibiting oligomeric compounds are capable of mediating expression of target nucleic acid sequences in liver cells, such as hepatocytes, which may be useful in the treatment of diseases or conditions that respond to inhibition of gene expression or activity in a cell, tissue, or organism.
1 - 20 . (canceled)
21 . A method of preparing Compound 10
comprising:
(i) reacting Compound 9
with 2-cyanoethyl-N,N,N′,N′-tetraisopropylphosphorodiamidite
in the presence of 4,5-dicyanoimidazole to form Compound 10.
22 . The method of claim 21 , further comprising
(ii-a) reacting Tosylate Salt 7
with Compound 8
in the presence of triethylamine to form Compound 9, wherein TFP is tetrafluorophenyl.
23 . The method of claim 22 , further comprising
(iii-a) hydrogenating Compound 6
with H 2 in the presence of Pd/C and p-toluenesulfonic acid to form Tosylate Salt 7.
24 . The method of claim 23 , further comprising
(iv-a) reacting Compound 4
with Compound 5
in the presence of 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium tetrafluoroborate (TBTU) and N,N-diisopropylethylamine (DIPEA) to form Compound 6.
25 . The method of claim 24 , further comprising
(v-a) reacting Compound 3
with formic acid to form Compound 4.
26 . The method of claim 25 , further comprising
(vi-a) reacting Compound 1
with Compound 2
in the presence of isobutyl chloroformate and N-methylmorpholine (NMM) to form Compound 3.
27 . The method of claim 21 , further comprising
(ii-b) reacting Tosylate Salt 7
with Compound 8
in the presence of N, N-diisopropylethylamine to form Compound 9, wherein TFP is tetrafluorophenyl.
28 . The method of claim 27 , further comprising
(iii-b) hydrogenating Compound 6
with H 2 in the presence of Pd/C and p-toluenesulfonic acid to form Tosylate Salt 7.
29 . The method of claim 28 , further comprising
(iv-b) reacting Compound 4
with Compound 5
in the presence of 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium tetrafluoroborate (TBTU) and N,N-diisopropylethylamine (DIPEA) to form Compound 6.
30 . The method of claim 29 , further comprising
(v-b) reacting Compound 3
with formic acid to form Compound 4.
31 . The method of claim 30 , further comprising
(vi-b) reacting Compound 1
with Compound 2
in the presence of isobutyl chloroformate and N-methylmorpholine (NMM) to form Compound 3.