Triethylamine → Tert-butyl 4-(5-{[5-(trifluoromethyl)pyridin-2-yl]ethynyl}pyridin-2-yl)piperazine-1-carboxylate

To a stirred solution of tert-butyl 4-(5-ethynylpyridin-2-yl)piperazine-1-carboxylate (509 mg, 1.77 mmol), 2-Bromo-5-trifluoromethylpyridine (400 mg, 1.77 mmol), triethylamine (0.74 mL, 5.31 mmol), and cuprous iodide (135 mg, 0.71 mmol) in DMA (20 mL) at 25° C. was added tetrakistriphenylphosphine palladium (0) (102 mg, 5 mol %). The reaction was then stirred for 1 hour. Volatiles were removed in vacuo, and the residue was azeotroped with toluene (2×10 mL). The residue was then dissolved in CH2Cl2 (10 mL) and washed with water (10 mL). The layers were then separated and the aqueous phase extracted with CH2Cl2 (2×100 mL). The combined organic extracts were then dried, (MgSO4), filtered and concentrated in vacuo. The residue was then purified by flash chromatography (silica gel, 25% EtOAc in hexanes) to give tert-butyl 4-(5-{[5-(trifluoromethyl)pyridin-2-yl]ethynyl}pyridin-2-yl)piperazine-1-carboxylate as a yellow solid (729 mg, 1.68 mmol, 95%).

1. customVolatiles were removed in vacuo
2. customthe residue was azeotroped with toluene (2×10 mL)
3. dissolutionThe residue was then dissolved in CH2Cl2 (10 mL)
4. washwashed with water (10 mL)
5. customThe layers were then separated
6. extractionthe aqueous phase extracted with CH2Cl2 (2×100 mL)
7. dry with materialThe combined organic extracts were then dried, (MgSO4),
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe residue was then purified by flash chromatography (silica gel, 25% EtOAc in hexanes)

ORD record

ord-377b485a81e940e992fb551998def9b8

Source dataset

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07153857B2