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

To a stirred solution of tert-butyl 4-(5-iodopyridin-2-yl)piperazine-1-carboxylate (1.0 g, 2.57 mmol, prepared as in Example 1), trimethylsilyl acetylene (0.73 mL, 5.14 mmol), triethylamine (1.11 mL, 7.71 mmol), and cuprous iodide (196 mg, 1.03 mmol) in DMA (20 mL) at 25° C. was added tetrakistriphenylphosphine palladium (0) (149 mg, 5 mol %). The reaction was stirred for 10 minutes. Volatiles were removed in vacuo. The residue was then dissolved in ethyl acetate (250 mL) and washed with water (100 mL). The layers were then separated and the aqueous phase extracted with ethyl acetate (250 mL). The combined organic extracts were then dried, (MgSO4), filtered and concentrated in vacuo. The residue was then purified by flash chromatography (silica gel, 10% EtOAc in hexanes) to give tert-butyl 4-{5-[(trimethylsilyl)ethynyl]pyridin-2-yl}piperazine-1-carboxylate as a pale brown solid (652 mg, 1.81 mmol, 70%).

1. customVolatiles were removed in vacuo
2. dissolutionThe residue was then dissolved in ethyl acetate (250 mL)
3. washwashed with water (100 mL)
4. customThe layers were then separated
5. extractionthe aqueous phase extracted with ethyl acetate (250 mL)
6. dry with materialThe combined organic extracts were then dried, (MgSO4),
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThe residue was then purified by flash chromatography (silica gel, 10% EtOAc in hexanes)

ORD-Eintrag

ord-088d98d42a744e67a75c49cdac7dabc7

Quelldatensatz

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07153857B2