Thiophene → 4,5-Dimethyl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one

HRID 252681Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 252681
[S:1]1[CH:5]=[CH:4][CH:3]=[CH:2]1.[C:6](O)(=[O:11])/[C:7](=[CH:9]/[CH3:10])/[CH3:8]>C(Cl)Cl>[CH3:10][CH:9]1[C:3]2[CH:4]=[CH:5][S:1][C:2]=2[C:6](=[O:11])[CH:7]1[CH3:8]

Komponenten

4

Edukt 2

HCID 8030ThiopheneHCID 125468Tiglic acid

Produkt 1

HCID 585261534,5-Dimethyl-4,5-dihydro-6H-cyclopenta[b]thiophen-6-one

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel

Versuchsvorschrift

To polyphosphoric acid (prepared from 500 g of P4O10 and 340 g of 85% H3PO4) a mixture of 47.6 ml (50.0 g, 0.60 mol) of thiophene and 59.5 g (0.60 mol) of tiglic acid in 80 ml of CH2Cl2 was added over 2.5 h at 50° C. This mixture was stirred at this temperature for 2 h, and, then, immersed in 1 kg of ice. The product was extracted with 3×300 ml of methyl-tert-butyl ether. The combined extract was washed with the saturated aqueous solution of Na2CO3, dried over K2CO3, and evaporated to dryness. Fractional distillation gave a colorless oil, bp 96-98° C./2 mm Hg. Yield 89.3 g (90%). On the evidence of NMR spectroscopy, the product is a mixture of two diastereomers (ca. 3:1).

Aufarbeitung

  1. additionwas added over 2.5 h at 50° C
  2. extractionThe product was extracted with 3×300 ml of methyl-tert-butyl ether
  3. extractionThe combined extract
  4. washwas washed with the saturated aqueous solution of Na2CO3
  5. dry with materialdried over K2CO3
  6. customevaporated to dryness
  7. distillationFractional distillation
  8. customgave a colorless oil, bp 96-98° C./2 mm Hg
  9. additiona mixture of two diastereomers (ca. 3:1)

Quellen und Nachweise

ORD-Eintrag
ord-462930b4ee974bb7920d6272dae6e0b9
Quelldatensatz
uspto-grants-2011_01
Patentnummer
US07868197B2

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