Tributyltin Chloride → 6-chloro-3-(tributylstannyl)-1H-indazole

In a round-bottomed flask, 6-chloro-3-iodo-1H-indazole (250 mg, 0.85 mmol) was dissolved in THF (5 ml) and sodium hydride (60% dispersion in mineral oil, 41 mg, 1.03 mmol) was added. The reaction mixture was stirred at room temperature for 10 min then cooled to −16° C. (NaCl/ice bath) and isopropylmagnesium chloride (2.0 M in THF, 0.52 ml, 1.04 mmol) was added dropwise. The reaction mixture was stirred at −16° C. for 30 min then additional isopropylmagnesium chloride (2.0 M in THF (0.14 ml, 0.28 mmol) was added. The reaction mixture was stirred at −16° C. for 10 min then tributylchlorostannane (0.28 ml, 1.03 mmol) was slowly added. The reaction mixture was allowed to warm to room temperature over 2.5 h then quenched with saturated NH4Cl-solution and extracted with EtOAc (2×). The combined organic layers were washed with water and brine then dried over sodium sulfate, filtered, concentrated to give 6-chloro-3-tributylstannanyl-1H-indazole as a yellow oil which was used without further purification.

1. additionwas added dropwise
2. stirringThe reaction mixture was stirred at −16° C. for 30 min
3. stirringThe reaction mixture was stirred at −16° C. for 10 min
4. temperatureto warm to room temperature over 2.5 h
5. customthen quenched with saturated NH4Cl-solution
6. extractionextracted with EtOAc (2×)
7. washThe combined organic layers were washed with water and brine
8. dry with materialthen dried over sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated

ORD record

ord-772d6b6378ca4f70bd5ddd683a7d4c37

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08658646B2