P-Toluenesultonic acid

The morphbiinBc enamitie of cyi clohexanone, 1-morpholino-l-cyclohexene, is prepared by refluxing a mixture of 1.5 moles of cyclohexanone, 1.8 moles of morpholine, 1.5 g. of p-toluenesultonic acid, and 300 ml. of toluene in a flask fitted with a water separator under a ireflux conden iser.- Separation of water commences at once... 

Fischer-type reaction of enhydrazine 74a with cyclohexanone in the presence of p-toluenesultonic acid afforded octahydrocarbazole 75 (R = Me), which can be oxidized with chloranil to tetrahydrocarbazole 76 (R = Me) (70CB1767). The carbazole 76 (R = H, Et) were obtained from the enamines 77 (R = H, Et) by photolysis in dioxane-acetonitrile containing triethylamine or by treatment with triphenylphosphine-palladium acetate complex (2 1) in DMF in the presence of NaHCCb... 

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