Tributyltin Chloride → HCID 59164465, compound

HRID 906544Notes

Reaction equation

HRID 906544 reaction equation
[CH3:1][C:2]1[CH:6]=[CH:5][N:4]([CH2:7][CH2:8][O:9][CH2:10][Si:11]([CH3:14])([CH3:13])[CH3:12])[N:3]=1.CC1N(CCOC[Si](C)(C)C)N=CC=1.[Li]CCCC.[CH2:34]([Sn:38](Cl)([CH2:43][CH2:44][CH2:45][CH3:46])[CH2:39][CH2:40][CH2:41][CH3:42])[CH2:35][CH2:36][CH3:37]>C1COCC1>[CH3:1][C:2]1[CH:6]=[C:5]([Sn:38]([CH2:39][CH2:40][CH2:41][CH3:42])([CH2:43][CH2:44][CH2:45][CH3:46])[CH2:34][CH2:35][CH2:36][CH3:37])[N:4]([CH2:7][CH2:8][O:9][CH2:10][Si:11]([CH3:13])([CH3:12])[CH3:14])[N:3]=1

Participants

6

Reactant 4

HCID 15096Tributyltin ChlorideHCID 59164412HCID 59164412, compoundHCID 59164512HCID 59164512, compoundHCID 178418339Butyllithium

Product 1

HCID 59164465HCID 59164465, compoundYield 24%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution containing a 1:1 mixture of 3-methyl-1-(2-trimethylsilanylmethoxy-ethyl)-1H-pyrazole and 5-methyl-1-(2-trimethylsilanylmethoxy-ethyl)-1H-pyrazole (1.5 g, 7.06 mmol) in THF (20 mL) at −78° C. was added dropwise n-BuLi (1.6M in hexanes, 4.4 mL, 1 equiv) while keeping the temperature below −70° C. The mixture was then stirred 30 min at −78° C. prior to the addition of tributyltin chloride (1.9 mL, 1 equiv) (the temperature was maintained below −70° C.). The mixture was stirred at −78° C. for 30 min and for 2 h at r.t. Hexanes was added to the mixture and the insoluble material was removed by filtration. Concentration of the solution in vacuo gave a colorless syrup. The crude product was purified by flash chromatography (hexanes to EtOAc/hexanes (20/80)) to provide 3-methyl-5-tributylstannanyl-1-(2-trimethylsilanylmethoxy-ethyl)-1H-pyrazole (847 mg, 24%) as a colorless syrup. (TLC rf 0.33 in EtOAc/hexanes 5:95).

Workup

  1. additionTo a solution containing
  2. customthe temperature below −70° C
  3. temperaturewas maintained below −70° C.)
  4. stirringThe mixture was stirred at −78° C. for 30 min and for 2 h at r.t
  5. customthe insoluble material was removed by filtration
  6. customConcentration of the solution in vacuo gave a colorless syrup
  7. customThe crude product was purified by flash chromatography (hexanes to EtOAc/hexanes (20/80))

Sources & evidence

ORD record
ord-0d08b2f1450f4fbe83a6d01d0162bafb
Source dataset
uspto-grants-2011_09
Patent number
US08012988B2

Reaction notes

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