Malic Acid → 7-hydroxy-5-methylcoumarin

HRID 1106265Notes

Reaction equation

HRID 1106265 reaction equation
[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

Participants

5

Reactant 3

HCID 525Malic AcidHCID 1118Sulfuric AcidHCID 10436Orcinol

Product 1

HCID 53556397-hydroxy-5-methylcoumarinYield 43.9%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

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##

Workup

  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)

Sources & evidence

ORD record
ord-cd5dce67e5074ffbb8fbe6dddbd51add
Source dataset
uspto-grants-1982_01
Patent number
US04312883

Reaction notes

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