Dimethylformamide → 2-Formyl-3-(4-methylphenyl)pyrrole

HRID 1921561Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1921561
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:12]=[CH:11][NH:10][CH:9]=2)=[CH:4][CH:3]=1.O=P(Cl)(Cl)Cl.CN([CH:21]=[O:22])C>C(Cl)Cl>[CH:21]([C:9]1[NH:10][CH:11]=[CH:12][C:8]=1[C:5]1[CH:4]=[CH:3][C:2]([CH3:1])=[CH:7][CH:6]=1)=[O:22]

Komponenten

5

Edukt 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 105349353-(4-Methylphenyl)pyrrole

Produkt 1

HCID 467385812-Formyl-3-(4-methylphenyl)pyrrole

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Versuchsvorschrift

Following a standard procedure (Balasubramanian, T. et al, J. Org. Chem. 2000, 65, 7919-7929), a solution of 7 (472 mg, 3.00 mmol) in DMF (0.96 mL) and CH2Cl2 (30 mL) under argon was cooled to 0° C. and then POCl3 (340 μL, 3.60 mmol) was added dropwise. After 1 h, the flask was warmed to room temperature and stirred overnight (˜18 h). The reaction was quenched at 0° C. with 2.5 M NaOH (25 mL). The mixture was poured into water (50 mL), extracted with CH2Cl2, and the combined organic layers were washed with water, brine, dried (NaSO4), and concentrated. The residue was chromatographed [silica, CH2Cl2/ethyl acetate (9:1)] to give a brown solid. 1H NMR spectroscopy showed two regioisomers in ˜13:1 ratio. Cooling of the solution (ethyl acetate/hexanes) at ˜−16° C. resulted in precipitation of an orange solid, which proved to be a single regioisomer (354 mg, 64%): mp 149-150° C.; 1H NMR δ 2.41 (s, 3H), 6.42-6.44 (m, 1H), 7.10-7.13 (m, 1H), 7.26 (d, J=8.0 Hz, 2H), 7.40 (d, J=8.0 Hz, 2H), 9.63-9.64 (m, 1H), 9.52-9.78 (br, 1H); 13C NMR δ 21.4, 111.6, 126.2, 128.9, 129.3, 129.7, 130.9, 137.7, 137.9, 180.2; FAB-MS obsd 186.0907, calcd 186.0919 (C12H11NO).

Aufarbeitung

  1. customThe reaction was quenched at 0° C. with 2.5 M NaOH (25 mL)
  2. additionThe mixture was poured into water (50 mL)
  3. extractionextracted with CH2Cl2
  4. washthe combined organic layers were washed with water, brine
  5. dry with materialdried (NaSO4)
  6. concentrationconcentrated
  7. customThe residue was chromatographed [silica, CH2Cl2/ethyl acetate (9:1)]
  8. customto give a brown solid
  9. customresulted in precipitation of an orange solid, which

Quellen und Nachweise

ORD-Eintrag
ord-1813d478ab9544a0b47761d3e0138fc7
Quelldatensatz
uspto-grants-2012_05
Patentnummer
US08173691B2

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