Acetic Anhydride → N-(2,2-Dimethyl-2H-1-benzopyran-7-yl)acetamide

HRID 1979547Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1979547
[CH3:1][C:2]1([CH3:15])[O:7][C:6]2[CH:8]=[C:9]([N+:12]([O-])=O)[CH:10]=[CH:11][C:5]=2[CH:4]=[CH:3]1.[C:16](OC(=O)C)(=[O:18])[CH3:17]>[Fe].C(O)(=O)C>[C:16]([NH:12][C:9]1[CH:10]=[CH:11][C:5]2[CH:4]=[CH:3][C:2]([CH3:15])([CH3:1])[O:7][C:6]=2[CH:8]=1)(=[O:18])[CH3:17]

Komponenten

5

Edukt 2

HCID 7918Acetic AnhydrideHCID 132228872,2-Dimethyl-7-nitro-2h-1-benzopyran

Produkt 1

HCID 14831889N-(2,2-Dimethyl-2H-1-benzopyran-7-yl)acetamide

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 23925IronKatalysatorHCID 176Acetic AcidLösungsmittel

Reaktionsbedingungen

Temperatur
120 °C

Versuchsvorschrift

2,2-Dimethyl-7-nitro-2H-benzo[b]pyran (40.00 g, the preparation of which is disclosed in British Patent No. 1,548,222), glacial acetic acid (200 ml), acetic anhydride (120 ml) and electrolytic iron powder (88 g) were stirred and heated at 120° C. for 16 hours. Dilution with water, extraction via chloroform followed by washing of the organic layer with water and sodium bicarbonate solution, drying evaporation etc., gave a crude gum which was chromatographed on a silica gel column using ethyl acetate -60°-80° petroleum ether mixtures in a gradient elution technique. Fractions homogeneous by TLC were combined and recrystallised from 60°-80° petroleum ether to give 7-acetamido-2-,2-dimethyl-2H-benzo[b]pyran (5.27 g) as white needles of mp 80°-81° C.; nmr (CDCl3) 1.39 (6H), 2.12 (3H), 5.48 (1H, d, J=10), 6.21 (1H, d, J=10), 6.76-7.34 (3H, m), 8.95 (1H). Anal. Calcd for C13H15NO2 ; C, 71.87; H, 696; N, 6.45. Found: C, 72.00; H, 7.11; N, 6.23%.

Aufarbeitung

  1. extractionDilution with water, extraction via chloroform
  2. washby washing of the organic layer with water and sodium bicarbonate solution
  3. customdrying
  4. customevaporation etc.
  5. customgave a crude gum which
  6. customwas chromatographed on a silica gel column
  7. customethyl acetate -60°-80° petroleum ether
  8. washmixtures in a gradient elution technique
  9. customrecrystallised from 60°-80° petroleum ether

Quellen und Nachweise

ORD-Eintrag
ord-14525c7c15f14feeaac35966acf254fa
Quelldatensatz
uspto-grants-1984_11
Patentnummer
US04481214

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