3-Pyridine aldoxime → 3-(4,5-Bis-trimethylsilanyl-isoxazol-3-yl)-pyridine

HRID 660180Notes

Reaction equation

HRID 660180 reaction equation
C1COCC1.[N:6]1[CH:11]=[CH:10][CH:9]=[C:8]([CH:12]=[N:13][OH:14])[CH:7]=1.ClN1C(=O)CCC1=O.[CH3:23][Si:24]([CH3:32])([CH3:31])[C:25]#[C:26][Si:27]([CH3:30])([CH3:29])[CH3:28]>C(OCC)(=O)C.C(N(CC)CC)C>[CH3:23][Si:24]([CH3:32])([CH3:31])[C:25]1[C:12]([C:8]2[CH:7]=[N:6][CH:11]=[CH:10][CH:9]=2)=[N:13][O:14][C:26]=1[Si:27]([CH3:30])([CH3:29])[CH3:28]

Participants

7

Reactant 4

HCID 6943-Pyridine aldoximeHCID 8028TetrahydrofuranHCID 31398ChlorosuccinimideHCID 84564Bis(trimethylsilyl)acetylene

Product 1

HCID 575480363-(4,5-Bis-trimethylsilanyl-isoxazol-3-yl)-pyridineYield 17%

Reagents, catalysts & solvents 2

HCID 8471TriethylamineSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
65 °C

Procedure

To a solution of anhydrous THF (250 ml) containing 3-pyridinealdoxim (61) (18.87 g, 154.7 mmol) were added 20.57 g (1.0 eq) of N-chlorosuccinimide. After the addition, the resulting solution was stirred for 18 hours at 65° C. Then the temperature of the reaction mixture was lowered to −30° C. and 1,2-bis-trimethylsilanyl-ethyne was added (26.4 g, 170.4 mmol), subsequently followed by triethylamine (2 eq, 42 ml, dropwise), while keeping the temperature <−25° C. After stirring for another 30 minutes, the mixture was allowed to warm to ambient temperature, diluted with ethyl acetate, washed three times with a saturated NaHCO3 solution, dried (Na2SO4), filtered and concentrated. The resulting residue was purified by flash chromatography (diethyl ether/PE 1/1) to afford 3-(4,5-bis-trimethylsilanyl-isoxazol-3-yl)-pyridine (62) as an oil (4.45 g, 17%). 1H-NMR (400 MHz, CDCl3): δ 8.70 (dd, J=5 Hz, 2 Hz, 1H), 8.68 (d, J=2 Hz, 1H), 7.76 (dt, J=8 Hz, 2 Hz, 1H), 7.41-7.37 (m, 1H), 0.46 (s, 9H), 0.011 (s, 9H).

Workup

  1. additionAfter the addition
  2. customwas lowered to −30° C.
  3. customthe temperature <−25° C
  4. stirringAfter stirring for another 30 minutes
  5. temperatureto warm to ambient temperature
  6. washwashed three times with a saturated NaHCO3 solution
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe resulting residue was purified by flash chromatography (diethyl ether/PE 1/1)

Sources & evidence

ORD record
ord-7d98dcdb73d34bcb9b543669271478a3
Source dataset
uspto-grants-2011_12
Patent number
US08084473B2

Reaction notes

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