Ethanol → ethyl 8-bromo-6-methoxy-4-oxo-4H-chromene-2-carboxylate

HRID 1181941

Reaktionsgleichung

Reaktionsgleichung von HRID 1181941
S(=O)(=O)(O)O.[Br:6][C:7]1[CH:21]=[C:20]([O:22][CH3:23])[CH:19]=[CH:18][C:8]=1[O:9]/[C:10](=[CH:14]\[C:15]([OH:17])=O)/[C:11]([OH:13])=[O:12].[CH2:24](O)[CH3:25]>>[Br:6][C:7]1[CH:21]=[C:20]([O:22][CH3:23])[CH:19]=[C:18]2[C:8]=1[O:9][C:10]([C:11]([O:13][CH2:24][CH3:25])=[O:12])=[CH:14][C:15]2=[O:17]

Komponenten

4

Edukt 3

HCID 702EthanolHCID 1118Sulfuric AcidHCID 69270394(2Z)-2-(2-bromo-4-methoxyphenoxy)-2-butenedioic acid

Produkt 1

HCID 22142256ethyl 8-bromo-6-methoxy-4-oxo-4H-chromene-2-carboxylateAusbeute 50 %

Versuchsvorschrift

Sulfuric acid (50 ml) was added to (2Z)-2-(2-bromo-4-methoxyphenoxy)-2-butenedioic acid (24.3 g, 86.6 mmol; as prepared in Reference Example 2b above). After heating the mixture with a heat gun for 5-10 min a clear deep brown solution was obtained. This solution was slowly added to refluxing absolute ethanol (250 ml). After the addition the reaction was refluxed for 30 min then allowed to cool. Crystals started to form after 20 min and the reaction was put in the refrigerator overnight. The solid was filtered, washed with cold ethanol/water 9:1 and dried to give ethyl 8-bromo-6-methoxy-4-oxo-4H-chromene-2-carboxylate as an off-white solid (12.3 g, 50% yield, mp 159-161° C.).

Aufarbeitung

  1. temperatureAfter heating the mixture with a heat gun for 5-10 min a clear deep brown solution
  2. customwas obtained
  3. additionThis solution was slowly added
  4. additionAfter the addition the reaction
  5. temperaturewas refluxed for 30 min
  6. temperatureto cool
  7. customto form after 20 min
  8. customwas put in the refrigerator overnight
  9. filtrationThe solid was filtered
  10. washwashed with cold ethanol/water 9:1
  11. customdried

Quellen und Nachweise

ORD-Eintrag
ord-64b368413a7d4ab48331f70a61faa0b2
Quelldatensatz
uspto-grants-2007_10
Patentnummer
US07285662B2

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