[Cl:1][C:2]1[CH:8]=[CH:7][CH:6]=[CH:5][C:3]=1[NH2:4].[CH3:9][C:10]1([CH3:18])[CH2:17][C:15](=O)[CH2:14][C:12](=[O:13])[CH2:11]1>C(O)C.C(O)(=O)C>[Cl:1][C:2]1[CH:8]=[CH:7][CH:6]=[CH:5][C:3]=1[NH:4][C:15]1[CH2:17][C:10]([CH3:18])([CH3:9])[CH2:11][C:12](=[O:13])[CH:14]=1A mixture of 12.75 parts of 2-chloroaniline and 14 parts of dimedone is dissolved in 40 volume parts of ethanol under warming, followed by the addition of 3 drops of glacial acetic acid. The solution is refluxed in a water bath for 2 hours, after which time the ethanol is distilled off and the resulting residue is allowed to cool, whereupon yellow crystals separate. These crystals are collected by filtration, washed with isopropyl ether and recrystallized from acetone. The procedure yields 3-(2-chloroanilino)-5,5-dimethyl-2-cyclohexen-1-one as colorless prisms melting at 150°-152° C.
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