Tributyltin Chloride → 1,6,6-trimethyl-3-tributylstannanyl-4,5,6,7-tetrahydro-1H-indazole

HRID 245976Notes

Reaction equation

HRID 245976 reaction equation
I[C:2]1[C:10]2[CH2:9][CH2:8][C:7]([CH3:12])([CH3:11])[CH2:6][C:5]=2[N:4]([CH3:13])[N:3]=1.C([Mg]Cl)(C)C.[CH2:19]([Sn:23]([CH2:29][CH2:30][CH2:31][CH3:32])([CH2:25][CH2:26][CH2:27][CH3:28])Cl)[CH2:20][CH2:21][CH3:22]>C1COCC1>[CH3:13][N:4]1[C:5]2[CH2:6][C:7]([CH3:12])([CH3:11])[CH2:8][CH2:9][C:10]=2[C:2]([Sn:23]([CH2:25][CH2:26][CH2:27][CH3:28])([CH2:29][CH2:30][CH2:31][CH3:32])[CH2:19][CH2:20][CH2:21][CH3:22])=[N:3]1

Participants

5

Reactant 3

HCID 15096Tributyltin ChlorideHCID 712795513-iodo-1,6,6-trimethyl-4,5,6,7-tetrahydro-1H-indazoleHCID 178418918HCID 178418918, compound

Product 1

HCID 712794751,6,6-trimethyl-3-tributylstannanyl-4,5,6,7-tetrahydro-1H-indazoleYield 52.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 3-iodo-1,6,6-trimethyl-4,5,6,7-tetrahydro-1H-indazole (0.150 g, 0.49 mmol) in THF (3 mL) at 0° C. was slowly added isopropylmagnesium chloride (2.0 M in THF) (0.30 mL, 0.59 mmol). The reaction mixture was stirred at 0° C. for 20 min then tributylchlorostannane (0.16 mL, 0.59 mmol) was added dropwise. The reaction mixture was stirred at 0° C. for 30 min then warmed to room temperature and stirred for 1 h. The reaction was quenched with water and extracted with EtOAc (2×). The combined organics were dried over MgSO4 and concentrated. The residue was purified by silica gel chromatography with 0% to 10% EtOAc/hexanes (0.5% Et3N) to afford 116 mg (52%) of 1,6,6-trimethyl-3-tributylstannanyl-4,5,6,7-tetrahydro-1H-indazole as a colorless oil. 1H NMR (CDCl3, 300 MHz): δ (ppm) 3.74 (s, 3H), 2.49 (t, J=6.4 Hz, 2H), 2.30 (s, 2H), 1.45-1.61 (m, 8H), 1.25-1.41 (m, 6H), 1.04-1.13 (m, 6H), 1.01 (s, 6H), 0.89 (t, J=7.2 Hz, 9H).

Workup

  1. customat 0° C.
  2. stirringThe reaction mixture was stirred at 0° C. for 30 min
  3. temperaturethen warmed to room temperature
  4. stirringstirred for 1 h
  5. customThe reaction was quenched with water
  6. extractionextracted with EtOAc (2×)
  7. dry with materialThe combined organics were dried over MgSO4
  8. concentrationconcentrated
  9. customThe residue was purified by silica gel chromatography with 0% to 10% EtOAc/hexanes (0.5% Et3N)

Sources & evidence

ORD record
ord-1e2b911e16ca42619fe47ba65dfff9c3
Source dataset
uspto-grants-2014_02
Patent number
US08658646B2

Reaction notes

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