Acetic Acid → (3-Cyano-4-oxo-4H-1-benzopyran-6-yl)methylene diacetate
Reaction equation
[CH3:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:9]=[C:8]([C:11]#[N:12])[C:7](=[O:13])[C:6]=2[CH:14]=1.C([O:18][C:19](=[O:21])[CH3:20])(=O)C.S(=O)(=O)(O)O.[C:27]([OH:30])(=[O:29])[CH3:28]>[O-2].[O-2].[O-2].[Cr+6]>[C:27]([O:30][CH:1]([O:18][C:19](=[O:21])[CH3:20])[C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:9]=[C:8]([C:11]#[N:12])[C:7](=[O:13])[C:6]=2[CH:14]=1)(=[O:29])[CH3:28]Participants
6
Procedure
To a solution of 9.25 parts of 6-methyl-4-oxo-4H-1-benzopyran-3-carbonitrile in a mixture of 100 parts by volume of acetic acid, 100 parts by volume of acetic anhydride and 10 parts by volume of 97% sulfuric acid kept at 5°-10° C, there was added 15.5 parts of chromium trioxide over a period of 4 hours under stirring. The reaction mixture was poured into 1500 parts by volume of ice-water to give precipitates, which were collected by filtration, washed with water and recrystallized from ethanol. The procedure yielded 8.19 parts of 6-diacetoxymethyl-4-oxo-4H-1-benzopyran-3-carbonitrile as colorless needles. Melting point: 185°-186° C
Workup
- customkept at 5°-10° C
- customto give
- customprecipitates
- filtrationwhich were collected by filtration
- washwashed with water
- customrecrystallized from ethanol
Sources & evidence
- ORD record
- ord-ff334486789b4a16b3f3898de6fb1b16
- Source dataset
- uspto-grants-1978_04
- Patent number
- US04085116
Reaction notes
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