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

HRID 1646424노트

반응식

HRID 1646424 반응식
[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

참가 물질

5

반응물 3

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

생성물 1

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

시약·촉매·용매 1

HCID 962Water용매2회

실험 절차

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##

후처리

  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

출처 및 근거

ORD 기록
ord-03c9f3e77dd741c59ed1e25616f3d0c3
출처 데이터셋
uspto-grants-1993_01
특허 번호
US05179217

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