Diphenylphosphine → 1-(Diphenylphosphinomethyl)pyrazole

HRID 844531Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 844531
[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

Komponenten

5

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

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.

Aufarbeitung

  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)

Quellen und Nachweise

ORD-Eintrag
ord-72046082e7cb434fb88c560f1450e0dd
Quelldatensatz
uspto-grants-2002_04
Patentnummer
US06380393B1

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