The reaction of 1,4-dihydro-4-phenylcinnoline (I) with methyl p-toluenesulfonate (A) and acetic acid by means of KOH in refluxing toluene gives 1-(N-methyl-N-acetylamino)-3-phenylindole (II), which is hydrolyzed by treatment with refluxing concentrated HCl to afford 1-methylamino-3-phenylindole (III). Finally, this compound is condensed with 2-dimethylaminoethyl chloride (IV) by means of sodium amide in refluxing toluene.