abstract |
Indoles of the formula can by reacting a phenylhydrazine of the formula which is not substituted in at least one ortho position with a ketone of the formula be prepared in an aqueous medium in the presence of an acidic compound, less than 5 equivalents, based on 1 mol of phenylhydrazine, of an acidic compound with a pK value of 1.3-4.5. |