4-Methyl-benzenesulfonic Acid 2-[3-(Dimethylphenylsilyl)cyclobutylidene]hydrazide is an intermediate used in synthesizing 2-Cyclobutenyl-3-trifluoromethyl-5-chloro-1H-indole-1-carboxylic Acid Ethyl Ester, which is synthesized from 5-chloro-2-oxindole (C375030), that is used in the preparation of novel GSK-3β inhibitors as anticancer agents.