Boron trifluoride → Z-3-(3-Pyridinylmethyl)imino-10beta-piran-2-OL

HRID 1350123Notes

Reaction equation

HRID 1350123 reaction equation
[OH:1][C:2]1([CH3:12])[C:7](=O)[CH2:6][CH:5]2[CH2:9][CH:3]1[C:4]2([CH3:11])[CH3:10].[N:13]1[CH:18]=[CH:17][CH:16]=[C:15]([CH2:19][NH2:20])[CH:14]=1.B(F)(F)F>C1C=CC=CC=1>[CH3:12][C:2]1([OH:1])[C:7](=[N:20][CH2:19][C:15]2[CH:14]=[N:13][CH:18]=[CH:17][CH:16]=2)[CH2:6][CH:5]2[CH2:9][CH:3]1[C:4]2([CH3:11])[CH3:10]

Participants

5

Reactant 3

HCID 6356Boron trifluorideHCID 310183-PyridinemethanamineHCID 112005Oxypinocamphone

Product 1

HCID 21094263Z-3-(3-Pyridinylmethyl)imino-10beta-piran-2-OLYield 52.4%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To a stirring solution of (−)-2-hydroxy-3-pinanone (10.00 g, 59.4 mmol) in benzene (500 mL) was added 3-pyridylmethylamine (6.66 mL, 65.4 mmol) in one portion. Boron trifluoride diethyletherate (0.7 mL, 5.9 mmol) was added in one portion and the reaction was refluxed under N2 for 5 h, then stirred at room temperature for an additional 16 h. The benzene was removed by rotary evaporation and the resulting residue was stirred in saturated NaHCO3 solution (100 mL) for 1 h. This was then extracted with chloroform (3×100 mL), and the combined extracts dried (Na2SO4), filtered and concentrated by rotary evaporation. The resulting dark brown oil was purified by column chromatography, using a chloroform:methanol gradient (5:1 to 1:1, v/v) as eluent. The light yellow oil was crystallized by dissolving in hot ethyl acetate (50 mL) and placed in a freezer at −4° C. for 16 h. After warming to room temperature, the crystals were filtered, washed with ice-cold ethyl acetate, and dried on a hi-vacuum pump to yield off-white crystals (8.04 g, 52.4% yield).

Workup

  1. temperaturethe reaction was refluxed under N2 for 5 h
  2. customThe benzene was removed by rotary evaporation
  3. stirringthe resulting residue was stirred in saturated NaHCO3 solution (100 mL) for 1 h
  4. extractionThis was then extracted with chloroform (3×100 mL)
  5. dry with materialthe combined extracts dried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated by rotary evaporation
  8. customThe resulting dark brown oil was purified by column chromatography
  9. customThe light yellow oil was crystallized
  10. dissolutionby dissolving in hot ethyl acetate (50 mL)
  11. waitplaced in a freezer at −4° C. for 16 h
  12. temperatureAfter warming to room temperature
  13. filtrationthe crystals were filtered
  14. washwashed with ice-cold ethyl acetate
  15. customdried on a hi-vacuum pump

Sources & evidence

ORD record
ord-bd8e4e3f535f4d9c8c1a01f32b2f8a9a
Source dataset
uspto-grants-2007_05
Patent number
US07214686B2

Reaction notes

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