Trimethylsilylacetylene → 4-((6-Ethynyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)methoxy)-7-methoxyquinoline

Participants

Reaction Conditions

Reaction Steps

Tri-t-butylphosphonium tetrafluoroborate (0.0377 g, 0.130 mmol), tris(dibenzylideneacetone)dipalladium (0.0594 g, 0.0649 mmol), trimethylsilyl acetylene (1.82 ml, 13.0 mmol), 4-((6-bromo-[1,2,4]triazolo[4,3-a]pyridin-3-yl)methoxy)-7-methoxyquinoline (0.500 g, 1.30 mmol) were taken up in dioxane (10 mL) and triethylamine (3 mL). Added CuI. Sealed in a tube and heated at 80° C. for 3 h. Concentrated. Took up in MeOH and added solid potassium carbonate (large excess). Allowed to stir for 30 min. Filtered through a plug of Celite and concentrated. Took up in 10% MeOH in DCM and filtered through a plug of silica gel to afford 4-((6-ethynyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)methoxy)-7-methoxyquinoline. MS m/z=331.0 [M+1]+. Calc'd for C19H14N4O2: 330.3. Step 2. To a mixture of 4-((6-ethynyl-[1,2,4]triazolo[4,3-a]pyridin-3-yl)methoxy)-7-methoxyquinoline (0.200 g, 0.605 mmol), trimethylsilylmethyl azide (0.156 g, 1.21 mmol), sodium ascorbate (0.240 g, 1.21 mmol) in THF (4 mL) and water (1 mL) was added 1 drop of a copper sulfate (0.00966 g, 0.0605 mmol) solution. Stirred for 1 h. Concentrated. Suspended in water and extracted with CH2Cl2 (3×5 mL). Dried over sodium sulfate and concentrated. Took up crude mixture in DMF (4 mL). Added cesium fluoride (0.368 g, 2.42 mmol) and heated to 60° for 1 h. Concentrated. Purified on RPHPLC. Fractions containing product were treated with 9% sodium carbonate and volatiles were removed in vacuo. Product crashed out of solution and was isolated by filtration. MS m/z=388.1 [M+1]+. Calc'd for C20H17N7O2: 387.4.

Provenance & Evidence