Veratrole → 4-(3,4-Dimethoxyphenyl)-4-oxobutanoic acid
Reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[O:9][CH3:10].[C:11]1(=[O:17])[O:16][C:14](=[O:15])[CH2:13][CH2:12]1.[Cl-].[Al+3].[Cl-].[Cl-]>>[CH3:1][O:2][C:3]1[CH:8]=[C:7]([C:11](=[O:17])[CH2:12][CH2:13][C:14]([OH:16])=[O:15])[CH:6]=[CH:5][C:4]=1[O:9][CH3:10]Participants
Procedure
The naphthalenes of formulas A and B are known to the art. Moreover, they can be prepared by conventional means. For example, 1,2-dimethoxybenzene is treated with succinic anhydride and aluminum chloride in a hydrocarbon solvent to afford 4-(3', 4'-dimethoxyphenyl)-4-oxobutanoic acid. This is reduced by treatment with sodium borohydride, hydrogenolyzed by treating with palladium charcoal catalyst and hydrogen to furnish 4-(3', 4'-dimethoxyphenyl) butanoic acid. The corresponding acid chloride is prepared such as by treatment with thionyl chloride, and the acid chloride is treated with aluminum chloride to afford 6,7-dimethoxy-1-tetralone. The tetralone is reduced and hydrogenolyzed by the means described above to furnish 6,7-dimethoxytetralin which is dehydrogenated by treating with palladium charcoal catalyst to afford 2,3-dimethoxy naphthalene. By utilizing 1-methyl-3-fluorobenzene in the above process, 6-methyl-8-fluoro-4-tetralone and 6-fluoro-8-methyl-4-tetralone (as intermediates) and 1-methyl-3-fluoro naphthalene and 1-fluoro-3-methyl naphthalene are prepared. The mixture of naphthalenes are separated by conventional means, such as vacuum distillation.
Workup
- customMoreover, they can be prepared by conventional means
Sources & evidence
- ORD record
- ord-5e4c2abf70934993a25388539e5d8853
- Source dataset
- uspto-grants-1976_08
- Patent number
- US03978116
Reaction notes
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