Tributyltin Chloride → 6-chloro-1-ethyl-3-tributylstannyl-1H-indazole

Temperature

0 °C

To a solution of 6-chloro-1-ethyl-3-iodo-1H-indazole (150 mg, 0.47 mmol) in THF (3 mL) at 0° C. was slowly added isopropylmagnesium chloride (2.0 M in THF, 0.28 mL, 0.56 mmol). The bright yellow heterogeneous reaction mixture was stirred at 0° C. for 20 min then tributylchlorostannane (0.15 mL, 0.56 mmol) was added dropwise. Stirring was continued at 0° C. for 20 min then at room temperature for 2 h. The reaction mixture was quenched with water and extracted with EtOAc (2×). The combined organics were washed with brine then dried over MgSO4 and concentrated. The exact reaction was repeated once more on the same scale. The residues from the two runs were combined and purified by silica gel chromatography with 10% to 50% EtOAc/heptane (0.5% Et3N) to provide 128 mg (29%) of 6-chloro-1-ethyl-3-tributylstannanyl-1H-indazole as a colorless oil.

1. customat 0° C.
2. stirringStirring
3. waitwas continued at 0° C. for 20 min
4. waitat room temperature for 2 h
5. customThe reaction mixture was quenched with water
6. extractionextracted with EtOAc (2×)
7. washThe combined organics were washed with brine
8. dry with materialthen dried over MgSO4
9. concentrationconcentrated
10. customThe exact reaction
11. custompurified by silica gel chromatography with 10% to 50% EtOAc/heptane (0.5% Et3N)

ORD record

ord-9ff42a06cf564510a6776b4076a7e674

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658646B2