Diphenylphosphine → 1-(Diphenylphosphinomethyl)pyrazole

HRID 844531Notes

Reaction equation

HRID 844531 reaction equation
[C:1]1([PH:7][C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C([Li])CCC.Cl.Cl[CH2:21][N:22]1[CH:26]=[CH:25][CH:24]=[N:23]1>O1CCCC1>[C:8]1([P:7]([CH2:21][N:22]2[CH:26]=[CH:25][CH:24]=[N:23]2)[C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1

Participants

5

Reactant 3

HCID 70017DiphenylphosphineHCID 122483031-(chloromethyl)-1H-pyrazole hydrochlorideHCID 178418339Butyllithium

Product 1

HCID 98350751-(Diphenylphosphinomethyl)pyrazoleYield 47%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

Diphenylphosphine (2.642 g, 14.2 mmol) is placed into a Schlenk flask with degassed tetrahydrofuran (50 ml). The solution is cooled to −78° C. and n-butyllithium (8.4 ml, 1.6 M in hexanes, 15.0 mmol) is added dropwise. The red solution is stirred at −78° C. for an additional 1 hour then the cooling bath is removed and the solution is stirred for 3 hours. The red solution is cooled to 0° C. and 1-(chloromethyl)pyrazole hydrochloride (0.698 g, 4.56 mmol) is added at once. The ice bath is removed and the reaction is stirred for 11 hours before adding degassed methanol (25 ml) and water (20 ml). The organic phase is separated and the aqueous phase is extracted with diethyl ether (3×10 ml). The organic phase is dried over magnesium sulfate, filtered and concentrated. The crude material is purified by chromatography (SiO2, 10% ethyl acetate/petroleum ether) to give 1-(diphenylphosphinomethyl)pyrazole as a white solid in 47% yield (0.574 g, 2.16 mmol). This material is characterized as follows: 1H NMR (CDCl3, 500 MHz) δ 7.49 (dd. J=2.0, 0.5 Hz, 1 H), 7.45-7.40 (m, 4 H), 7.40-7.35 (m, 6 H), 7.25 (dd, J=2.5, 0.5 Hz, 1 H), 6.19 (dd, J=2.5, 2.0 Hz, 1 H), 4,91 (d, J=4.5 Hz, 2 R); 13C{1H} NMR (CDCl3, 125 MHz) δ 139.50, 136.04 (d, J=13.4 Hz), 133.18 (d, J=19.3 Hz), 129.34, 129.49, 128.95 (d, J=6.4 Hz), 106.11, 53.01 (d, J=16.0 Hz); 13P{1H} NMR (CDCl3, 80 MHz) δ−14.98.

Workup

  1. customthe cooling bath is removed
  2. stirringthe solution is stirred for 3 hours
  3. temperatureThe red solution is cooled to 0° C.
  4. customThe ice bath is removed
  5. stirringthe reaction is stirred for 11 hours
  6. additionbefore adding
  7. customdegassed methanol (25 ml) and water (20 ml)
  8. customThe organic phase is separated
  9. extractionthe aqueous phase is extracted with diethyl ether (3×10 ml)
  10. dry with materialThe organic phase is dried over magnesium sulfate
  11. filtrationfiltered
  12. concentrationconcentrated
  13. customThe crude material is purified by chromatography (SiO2, 10% ethyl acetate/petroleum ether)

Sources & evidence

ORD record
ord-72046082e7cb434fb88c560f1450e0dd
Source dataset
uspto-grants-2002_04
Patent number
US06380393B1

Reaction notes

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