Carbon Dioxide → 7-hydroxy-5-methylcoumarin

HRID 2081371Notes

Reaction equation

HRID 2081371 reaction equation
O.[CH3:2][C:3]1[CH:4]=[C:5]([OH:10])[CH:6]=[C:7]([CH:9]=1)[OH:8].C(O)(=O)[CH:12]([CH2:14][C:15](O)=O)[OH:13].S(=O)(O)[O-].[Na+].C(=O)=O>S(=O)(=O)(O)O>[OH:8][C:7]1[CH:6]=[C:5]2[C:4]([CH:15]=[CH:14][C:12](=[O:13])[O:10]2)=[C:3]([CH3:2])[CH:9]=1

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 525Malic AcidHCID 3083941Resorcinol, 5-methyl-, monohydrateHCID 23665763Sodium Bisulfite

Product 1

HCID 53556397-hydroxy-5-methylcoumarinYield 62%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

5-methylresorcinol monohydrate (284 gm, 2.0 mol; Aldrich) was thoroughly mixed with malic acid (280 gm, 2.10 mol; Aldrich) and then placed in a reaction flask containing sulfuric acid (600 ml) and a trace of sodium bisulfite (1.0 gm; Aldrich). The reaction mixture was heated to 90.C while being mechanically stirred until evolution of carbon dioxide subsided (about 5 hours). The resulting reddish-orange solution was poured into sufficient ice (with vigorous stirring) to make up 1 liter. The receiving flask was maintained at 0.C by external cooling until the addition of the reaction mixture was complete. The resulting light-orange product that precipitated was collected by suction filtration then washed thoroughly with water. The crude product was air dried on the filter, then recrystallized twice from tetramethylene glycol (1800 ml) to give pure 7-hydroxy-5-methylcoumarin (H5MC,l) as product (220 gm, 62% yield; mp 252°-255° C.).

Workup

  1. customplaced in a reaction flask
  2. custom(about 5 hours)
  3. additionThe resulting reddish-orange solution was poured into sufficient ice (with vigorous stirring)
  4. temperatureby external cooling until the addition of the reaction mixture
  5. customThe resulting light-orange product that precipitated
  6. filtrationwas collected by suction filtration
  7. washthen washed thoroughly with water
  8. customdried on the filter
  9. customrecrystallized twice from tetramethylene glycol (1800 ml)

Sources & evidence

ORD record
ord-e308ef69e6a64264875fcdd1eab47aa7
Source dataset
uspto-grants-1993_02
Patent number
US05184020

Reaction notes

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