Ethyl 2-methylacetoacetate → 7-hydroxy-3,4-dimethyl-2H-chromen-2-one

Reaction equation

[C:1]1([CH:8]=[CH:7][CH:6]=[C:4]([OH:5])[CH:3]=1)[OH:2].[CH3:9][CH:10]([C:16]([CH3:18])=O)[C:11](OCC)=[O:12].S(=O)(=O)(O)O>>[CH3:9][C:10]1[C:11](=[O:12])[O:2][C:1]2[C:8]([C:16]=1[CH3:18])=[CH:7][CH:6]=[C:4]([OH:5])[CH:3]=2

Participants

Reactant 3

HCID 701Ethyl 2-methylacetoacetate

HCID 1118Sulfuric Acid

HCID 5054Resorcinol

Product 1

HCID 54129907-hydroxy-3,4-dimethyl-2H-chromen-2-oneYield 83%

Procedure

Resorcinol (5.5 g) and 7.2 g of ethyl 2-methylacetoacetate were stirred at 10° C. for 3 hours in the presence of a catalytic amount concentrated sulfuric acid to give 7.8 g (yield 83%) of 3,4-dimethyl-7-hydroxycoumarin. The product was hydrogenated and dehydrated as in Referential Example 16 to give 5.7 g (78%) of the desired product as a pale brown liquid.

Sources & evidence

ORD record: ord-789ae70f296949a19bfdbf70c39a5de3
Source dataset: uspto-grants-1989_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04838924

Reaction notes

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