3-(4-Chlorbutyl)-1H-indol-5-carbonitril can be obtained from 5-cyanoindole and 4-chlorobutyryl chloride via acylation and reduction reactions. First, using 5-cyanoindole and 4-chlorobutyryl chloride as raw materials, and dichloromethane as solvent, 5-cyanoindole was acylated by FC reaction under the catalysis of isobutylaluminum dichloride to obtain chlorobutyryl-substituted 5-cyanoindole (yield 82%). Then, again in dichloromethane, using isobutylaluminum dichloride as catalyst and sodium borohydride as reducing agent, the target compound 3-(4-Chlorbutyl)-1H-indol-5-carbonitril was successfully synthesized.
