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

反応式

[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

参加物

反応物 3

HCID 1118Sulfuric Acid

HCID 8868Ethyl Acetoacetate

HCID 103331,3-Benzenediol, 4-methyl-

生成物 1

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

実験手順

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##