Diethyl benzylphosphonate → HCID 67735995, compound

HRID 864367Notes

Reaction equation

HRID 864367 reaction equation
[CH2:1](P(=O)(OCC)OCC)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C[O-].[Na+].[F:19][C:20]1[CH:21]=[N:22][CH:23]=[CH:24][C:25]=1[CH:26]=O>CN(C)C=O>[F:19][C:20]1[CH:21]=[N:22][CH:23]=[CH:24][C:25]=1/[CH:26]=[CH:1]\[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 14122Diethyl benzylphosphonateHCID 27630033-FluoroisonicotinaldehydeHCID 10942334Sodium Methoxide

Product 1

HCID 67735995HCID 67735995, compoundYield 10%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

Diethyl benzylphosphonate (2.8 ml, 13.4 mmol) was added to a solution of sodium methoxide (0.75 g, 13.6 mmol) in anhydrous dimethylformamide (15 ml) and the resultant mixture stirred at room temperature, under nitrogen, for ten minutes. A solution of 3-fluoropyridine-4-carboxaldehyde [prepared by the method of F. Marsais and G. Queguiner, Tetrahedron, 1983, 39, 2009] (1.55 g, 12.4 mmol) in anhydrous dimethylformamide (10 ml) was added and the reaction mixture stirred at room temperature under nitrogen for 21 hours. The reaction mixture was poured into ice-water (125 ml), the precipitated solid collected under suction and washed with water. The aqueous filtrate was extracted with ethyl acetate (100 ml), the extract dried (MgSO4) and concentrated in vacuo to an off. This off and the solid product were combined and purified by flash chromatography, eluting with 1:2 then 1:1 ethyl acetate/petrol (60°-80° C.), to afford (Z)-3-fluoro-4-(2-phenylethenyl)pyridine (0.25 g, 10%) as a colourless off; δH (CDCl3) 6.55 (1H, d, J 12.3Hz, CH=CHPh), 6.92 (1H, d, J 12.3Hz, CH=CHPh), 7.10 (1H, t, J 5.6Hz, ArH), 7.18-7.27 (5H, m, ArH), 8.18 (1H, d, J 4.9Hz, 6-H) and 8.43 (1H, s, 2-H); and (E)-3-fluoro-4-(2-phenylethenyl)pyridine (0.69 g, 28%) as a white solid; δH (CDCl3) 7.20 (1H, d, J 16.5Hz, CH=CHPh), 7.33-7.43 (4H, m, CH=CHPh and ArH), 7.51 (1H, m, ArH), 7.57 (2H, m, ArH), 8.37 (1H, d, J 5.1Hz, 6-H) and 8.47 (1H, d, J 2.2Hz, 2-H).

Workup

  1. customthe precipitated solid collected under suction
  2. washwashed with water
  3. extractionThe aqueous filtrate was extracted with ethyl acetate (100 ml)
  4. dry with materialthe extract dried (MgSO4)
  5. concentrationconcentrated in vacuo to an off
  6. custompurified by flash chromatography
  7. washeluting with 1:2

Sources & evidence

ORD record
ord-504e47a4037e482f9a7adcf51ef9fa31
Source dataset
uspto-grants-1996_10
Patent number
US05563150

Reaction notes

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