Acetic Anhydride → 6-Methyl-2-oxo-2H-1-benzopyran-7-yl acetate

HRID 1646424ノート

反応式

HRID 1646424 の反応式
[CH3:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[OH:12])[O:8][C:7](=[O:13])[CH:6]=[CH:5]2.[C:14](OC(=O)C)(=[O:16])[CH3:15].C(O[Na])(C)=O>O>[CH3:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[O:12][C:14](=[O:16])[CH3:15])[O:8][C:7](=[O:13])[CH:6]=[CH:5]2

参加物

5

反応物 3

HCID 7918Acetic AnhydrideHCID 54129132H-1-Benzopyran-2-one, 7-hydroxy-6-methyl-HCID 178418247HCID 178418247、化合物

生成物 1

HCID 132989326-Methyl-2-oxo-2H-1-benzopyran-7-yl acetate

試薬・触媒・溶媒 1

HCID 962Water溶媒2 回

実験手順

To prepare the alkylangelicins with an alkyl group in the 4'-position of the furan ring, the suitable umbelliferones, (I), (II), (III) were acetylated and the 7-acetoxycoumarins thus obtained were submitted to the Fries rearrangement. The 8-acetylumbelliferones were converted into the ethyl esters of the 7-(8-a-cetylcoumarinyl)oxyacetic acids, which were then hydrolized and cyclized yielding the desired 4'-methylangelicins. In such a manner a mixture of 6-methyl-7-hydroxycoumarin (I) (10.0 g), acetic anhydride (40 ml) and anhydrous AcONa (4.0 g) was refluxed for 1 h. To the reaction mixture an equal volume of H2O was cautiously added and the whole was refluxed for 10 min. The mixture was diluted with H2O (300 ml), chilled and the precipitate was collected by filtration, washed several times with H2O, dried and crystallized from MeOH, yielding the 6-methyl-7-acetoxycoumarin (XXII) (10.0 g; m.p. 147° C.). ##STR27##

後処理

  1. customhydrolized and cyclized yielding the desired 4'-methylangelicins
  2. temperaturewas refluxed for 1 h
  3. temperaturethe whole was refluxed for 10 min
  4. temperaturechilled
  5. filtrationthe precipitate was collected by filtration
  6. washwashed several times with H2O
  7. customdried
  8. customcrystallized from MeOH

出典と根拠

ORDレコード
ord-03c9f3e77dd741c59ed1e25616f3d0c3
出典データセット
uspto-grants-1993_01
特許番号
US05179217

反応ノート

読み込み中…