N-bromobutanimide → 6,8-di-t-butyl-4-oxo-4H-1-benzopyran-2-carboxylic acid, ethyl ester

HRID 1606326Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1606326
[C:1]([C:5]1[CH:6]=[C:7]([C:21]([CH3:24])([CH3:23])[CH3:22])[C:8]2[O:13][CH:12]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH2:11][C:10](=[O:19])[C:9]=2[CH:20]=1)([CH3:4])([CH3:3])[CH3:2].BrN1C(=O)CCC1=O>C(Cl)(Cl)(Cl)Cl>[C:1]([C:5]1[CH:6]=[C:7]([C:21]([CH3:22])([CH3:24])[CH3:23])[C:8]2[O:13][C:12]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[CH:11][C:10](=[O:19])[C:9]=2[CH:20]=1)([CH3:4])([CH3:3])[CH3:2]

Komponenten

4

Versuchsvorschrift

A mixture of 3.32 parts of 6,8-di-t-butyl-2,3-dihydro-4-oxo-4H-1-benzopyran-2-carboxylic acid, ethyl ester and 1.84 parts of N-bromosuccinimide was refluxed in 150 parts of carbon tetrachloride for six hours. The solution was cooled and then washed with water. The carbon tetrachloride extract was dried and the solvent was removed by evaporation. The resulting brown residue was crystallised from light petroleum (b.p. 40°-60°C) to give 1.69 parts of 6,8-di-t-butyl-4-oxo-4H-1-benzopyran-2-carboxylic acid, ethyl ester, m.p. 130°-131.5°C. The ester was hydrolysed to the sodium salt using the process of Example 5.

Aufarbeitung

  1. temperatureThe solution was cooled
  2. washwashed with water
  3. extractionThe carbon tetrachloride extract
  4. customwas dried
  5. customthe solvent was removed by evaporation
  6. customThe resulting brown residue was crystallised from light petroleum (b.p. 40°-60°C)

Quellen und Nachweise

ORD-Eintrag
ord-9fdadde0acae4980a6283e7c9c72a9bb
Quelldatensatz
uspto-grants-1976_04
Patentnummer
US03952104

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