Tributyltin Chloride → 1-Methyl-3-tributylstannanyl-1,4,5,6,7,8-hexahydrocycloheptapyrazole

温度

-10 °C

To a solution of 3-iodo-2-methyl-2,4,5,6,7,8-hexahydrocycloheptapyrazole (180 mg, 0.62 mmol) in THF (3 mL) at −10° C. (ice/acetone) was slowly added isopropylmagnesium chloride (2.0 M in THF, 0.37 mL, 0.74 mmol). The reaction mixture was stirred at −10° C. for 30 min then additional isopropylmagnesium chloride (2.0 M in THF, 0.10 mL, 0.20 mmol) was added. Stirring was continued at −10° C. for 20 min then tributylchlorostannane (0.20 mL, 0.74 mmol) was added dropwise. The reaction mixture was warmed to room temperature and stirred for 1 h then quenched with water and extracted with EtOAc (2×). The organics were dried over MgSO4 and concentrated. The residue was purified by silica gel chromatography with 0% to 10% EtOAc/hexanes (0.5% Et3N spike in hexanes) to afford 76 mg (28%) of 1-methyl-3-tributylstannanyl-1,4,5,6,7,8-hexahydrocycloheptapyrazole as a colorless oil. 1H NMR (CDCl3, 400 MHz): δ (ppm) 3.82 (s, 3H), 2.66-2.76 (m, 2H), 2.50-2.60 (m, 2H), 1.80-1.89 (m, 2H), 1.61-1.74 (m, 4H), 1.51-1.61 (m, 6H), 1.29-1.41 (m, 6H), 1.04-1.12 (m, 6H), 0.91 (t, J=7.3 Hz, 9H).

1. customat −10° C.
2. stirringStirring
3. waitwas continued at −10° C. for 20 min
4. temperatureThe reaction mixture was warmed to room temperature
5. stirringstirred for 1 h
6. customthen quenched with water
7. extractionextracted with EtOAc (2×)
8. dry with materialThe organics were dried over MgSO4
9. concentrationconcentrated
10. customThe residue was purified by silica gel chromatography with 0% to 10% EtOAc/hexanes (0.5% Et3N spike in hexanes)

ORDレコード

ord-3eb4ec8ac3054975aefe9834c5ec85f9

出典データセット

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08658646B2