Sulfuric Acid → 7-Hydroxy-4,6-dimethyl-2H-1-benzopyran-2-one

HRID 1646418Notes

Reaction equation

HRID 1646418 reaction equation
[OH:1][C:2]1C=C(O)[CH:5]=[CH:4][C:3]=1[CH3:9].OS(O)(=O)=O.[CH2:15]([O:17][C:18](=[O:23])[CH2:19][C:20]([CH3:22])=O)[CH3:16]>>[CH3:22][C:20]1[C:5]2[C:15](=[CH:16][C:2]([OH:1])=[C:3]([CH3:9])[CH:4]=2)[O:17][C:18](=[O:23])[CH:19]=1

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 8868Ethyl AcetoacetateHCID 103331,3-Benzenediol, 4-methyl-

Product 1

HCID 107977397-Hydroxy-4,6-dimethyl-2H-1-benzopyran-2-one

Procedure

A solution of 2,4-dihydroxytoluene (10.0 g) in ethylacetoacetate (12 ml) was poured in small portion into conc. H2SO4 (26 ml), chilling in an ice bath. After the addition was completed the solid obtained was separated by filtration, washed several times with water up to neutrality of the washings, dried and crystallized from MeOH, yielding 4,6-dimethyl-7-hydroxycoumarin (III) (10.64 g; m.p. 273° C.). ##STR8##

Workup

  1. temperaturechilling in an ice bath
  2. additionAfter the addition
  3. customobtained
  4. customwas separated by filtration
  5. washwashed several times with water up to neutrality of the washings
  6. customdried
  7. customcrystallized from MeOH

Sources & evidence

ORD record
ord-63bb26e6d78f4a3ea89c0b6a104acf43
Source dataset
uspto-grants-1993_01
Patent number
US05179217

Reaction notes

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