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

HRID 359496

Reaction equation

HRID 359496 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.). ##STR9##

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-d9d006fbc7f34f76bf56b49995c94735
Source dataset
uspto-grants-1991_03
Patent number
US05001147

Linked notes

Loading…