Malic Acid → 7-hydroxy-5-methylcoumarin

HRID 1106265Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1106265
[CH3:1][C:2]1[CH:3]=[C:4]([OH:9])[CH:5]=[C:6]([CH:8]=1)[OH:7].C(O)(=O)[CH:11]([CH2:13][C:14](O)=O)[OH:12].OS(O)(=O)=O>O>[CH3:1][C:2]1[CH:3]=[C:4]([OH:9])[CH:5]=[C:6]2[C:8]=1[CH:14]=[CH:13][C:11](=[O:12])[O:7]2

Komponenten

5

Edukt 3

HCID 525Malic AcidHCID 1118Sulfuric AcidHCID 10436Orcinol

Produkt 1

HCID 53556397-hydroxy-5-methylcoumarinAusbeute 43,9 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel

Versuchsvorschrift

A mixture of 5-methylresorcin (25.0 g), malic acid (26.0 g) and conc.H2SO4 (55 ml) was gently heated with the gaseous development almost ceased. The reaction mixture was then poured with vigorous stirring into a mixture of water and ice (700 ml), and stirred until the gummy mass initially formed was completely dispersed. The precipitate was collected by filtration, washed with water and crystallized twice (Me2CO) producing 5-methyl-7-hydroxycoumarin (I; 15 g; m.p. 256° C.) ##STR4## free from the isomer 5-hydroxy-7-methylcoumarin (II). ##STR5##

Aufarbeitung

  1. additionThe reaction mixture was then poured
  2. custominitially formed
  3. additionwas completely dispersed
  4. filtrationThe precipitate was collected by filtration
  5. washwashed with water
  6. customcrystallized twice (Me2CO)

Quellen und Nachweise

ORD-Eintrag
ord-cd5dce67e5074ffbb8fbe6dddbd51add
Quelldatensatz
uspto-grants-1982_01
Patentnummer
US04312883

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