REACTIONS OF 1-VINYL-4,5,6,7-TETRAHYDROINDOLE AND ITS MIXTURES WITH 4,5,6,7-TETRAHYDROINDOLE IN THE PRESENCE OF Cr- AND Pd-COATED CATALYSTS

Article abstract of DOI:10.1007/BF00961309

In the presence of Cr- and Pd-coated γ-alumina catalysts. 1-vinyl-4,5,6,7-tetrahydroindole (VTHI) and its mixtures with 4,5,6,7-tetrahydroindole (THI) are converted into 1-ethyl-4,5,6,7-tetrahydroindole (1-ETHI), indole, and 2-ethylindole, in proportions dependent on the reaction conditions and the catalyst.Over a sulfided 1percent Pd-γ-alumina catalyst in the presence of hydrogen at 200 deg C, VTHI is converted into 1-ETHI and THI.When the temperature is raised to 300-350 deg C, indole is formed in addition to these products.A 1:1 mixture of VTHI and THI over 1percent Pd-γ-alumina at 300 deg C gives indole and 2-ethylindole, over a sulfided 1percent Pd-γ-alumina catalyst at 200 deg C, 1-ETHI, and over a Cr oxide catalyst at 500 deg C, indole.