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

HRID 1037711Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1037711
[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 hours at 50° C. This mixture was stirred at this temperature for 2 hours, 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 a 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 was a mixture of two diastereomers (ca. 3:1).

Aufarbeitung

  1. additionwas added over 2.5 hours 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 a 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-40f0ddf1dbd947499948cba82319c7ea
Quelldatensatz
uspto-grants-2013_10
Patentnummer
US08546595B2

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