Tributyltin Chloride → 3-Cyclopropyl-5-(tributylstannyl)isothiazole

HRID 2173017Notes

Reaction equation

HRID 2173017 reaction equation
[CH:1]1([C:4]2[CH:8]=[C:7](I)[S:6][N:5]=2)[CH2:3][CH2:2]1.C([Li])CCC.[CH2:15]([Sn:19]([CH2:25][CH2:26][CH2:27][CH3:28])([CH2:21][CH2:22][CH2:23][CH3:24])Cl)[CH2:16][CH2:17][CH3:18].C(=O)(O)[O-].[Na+]>C1COCC1>[CH:1]1([C:4]2[CH:8]=[C:7]([Sn:19]([CH2:21][CH2:22][CH2:23][CH3:24])([CH2:25][CH2:26][CH2:27][CH3:28])[CH2:15][CH2:16][CH2:17][CH3:18])[S:6][N:5]=2)[CH2:3][CH2:2]1

Participants

6

Reactant 4

HCID 15096Tributyltin ChlorideHCID 516892Sodium BicarbonateHCID 711438323-Cyclopropyl-5-iodoisothiazoleHCID 178418339Butyllithium

Product 1

HCID 711438693-Cyclopropyl-5-(tributylstannyl)isothiazoleYield 87%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

To a cold (−78° C.) solution of 3-cyclopropyl-5-iodoisothiazole (100 mg, 0.398 mmol) in anhydrous THF (2.0 mL) was added n-butyllithium (0.299 mL, 0.478 mmol) dropwise. The reaction mixture was stirred for 60 minutes at −78° C. A solution of tributylchlorostannane (0.129 mL, 0.478 mmol) in anhydrous THF (2.0 mL) was added to the reaction mixture, which was stirred for 30 minutes −78° C. and subsequently allowed to warm to ambient temperature over a 1 hour period. Saturated aqueous sodium bicarbonate was added to the reaction mixture. The aqueous phase was extracted with EtOAc and the combined organic phase was dried over anhydrous sodium sulfate, filtered, and evaporated in vacuo. The residue was purified by silica gel chromatography (Flash 60 column) eluting with hexane/EtOAc (19:1) to give the title compound as a colorless oil (142.8 mg, 87%). 1H NMR (500 MHz, CDCl3) δ ppm 0.85-0.93 (m, 9H), 0.95-1.05 (m, 4H), 1.09-1.17 (m, 6H), 1.28-1.38 (m, 6H), 1.47-1.61 (m, 6H), 2.20-2.29 (m, 1H), 6.93 (s, 1H).

Workup

  1. stirringwas stirred for 30 minutes −78° C.
  2. temperatureto warm to ambient temperature over a 1 hour period
  3. extractionThe aqueous phase was extracted with EtOAc
  4. dry with materialthe combined organic phase was dried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. customevaporated in vacuo
  7. customThe residue was purified by silica gel chromatography (Flash 60 column)
  8. washeluting with hexane/EtOAc (19:1)

Sources & evidence

ORD record
ord-f42458e7c3c5485a9436e3e489106c39
Source dataset
uspto-grants-2015_06
Patent number
US09056873B2

Reaction notes

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