PREPARATION OF INDOLE COMPOUND

PURPOSE:To prepare an indole compound in high yield and space-time yield, by contacting an aniline compound with ethylene glycol using cadmium sulfate catalyst and a catalyst containing thallium sulfate and vanadyl sulfate. CONSTITUTION:Indole is prepared by contacting the aniline compound of formula (R is H, alkyl, alkoxy, halogen, tc.; R is H or alkyl) with ethylene glycol. The reaction is carried out in the presence of a catalyst composed of cadmium sulfate and a catalyst containing thallium sulfate and vanadyl sulfate, at 250- 450 deg.C, preferably 300-400 deg.C. The yield and the space-time yield of the reaction are as high as about >=70% and about >=35g/1-catalyst, hr, respectively.