Reaction equation
[CH:1]1[C:6]([C:7]([OH:9])=[O:8])=[CH:5][C:4]2[C:10]([O:12][C:13](=O)[C:3]=2[CH:2]=1)=[O:11].[CH:15]([C:18]1[CH:23]=[CH:22][C:21]([CH2:24]C(O)=O)=[CH:20][CH:19]=1)([CH3:17])[CH3:16]>>[CH:15]([C:18]1[CH:23]=[CH:22][C:21]([CH:24]=[C:2]2[CH:1]=[C:6]([C:7]([OH:9])=[O:8])[CH:5]=[C:4]3[CH:3]2[CH2:13][O:12][C:10]3=[O:11])=[CH:20][CH:19]=1)([CH3:17])[CH3:16]Participants
3
Procedure
Benzene-1,2,4-tricarboxylic anhydride and p-isopropylphenylacetic acid are reacted together as described in Example IA to give a mixture of benzylidenephthalide carboxylic acids. Fractional crystallization of this mixture from aqueous ethanol yields 2-(p-ispropylbenzylidene)phthalide-5-carboxylic acid as the less soluble isomer, and 4-(p-isopropylbenzylidene)phthalide-6-carboxylic acid as the more soluble isomer. By following the rest of the procedure set forth in part A of this example, 2-carboxy-7-isopropyl-10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene was obtained with a m.p. of 178°-182° C.
Workup
- customto give
- customFractional crystallization of this mixture from aqueous ethanol
Sources & evidence
- ORD record
- ord-2f211d6b1564404fad0deafa37f93fdd
- Source dataset
- uspto-grants-1977_08
- Patent number
- US04041173
Linked notes
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