4-Chloroindole is a reagent for chemical synthesis. One of the most popular applications involves reacting 4-Chloroindole with acetic acid to produce 4-Chloroindole-3-acetic acid (4-Cl-IAA), an auxin, which is a natural plant hormone and may be a death signaling hormone for maturing seeds.

4-Chlorophenylhydrazine is a reagent used for chemical synthesis. It is a reactant in the synthesis of 5-Aminopyrazole-4-carbonitriles.

4-CPPU is a cytokinin class plant growth regulator that is used to promote plant cell division. This compound has been used to increase embryogenic potential by inducing somatic embryogenesis, assist in plant callus production and investigate effects on plant biomass growth. 4-CPPU has also been shown to stimulate organogenesis in some plant species, such as Rubus.

4-Cyanoindole is a reagent for chemical synthesis. It is a reagent for the synthesis of beta3 agonists, calcium receptor modulators and tryptophan dioxygenase inhibitors immunomodulators.

4-Cyclohexylbutyl-4-O-(a-D-glucopyranosyl)-b-D-glucopyranoside, more commonly known as Cymal-4, is a maltose based detergent. Maltoside based detergents are mostly used to solubilize and purify membrane proteins.

4-hydroxy-2-methylindole is a reagent used for chemical synthesis. It has been used as the starting reagent in the synthesis for prostaglandin D2 receptor antagonists and substituted 4h-chromene apoptosis inducers and potential anti-cancer agents.

4-Isothiocyanatophenyl-alpha-D-mannopyranoside is an organic isothiocyanate compound used in carbohydrate chemistry. It is a building block and reagent which is used for preparing neoglycoproteins. This solid powder carbohydrate melts at 179-182°C. β-D-mannoside is a component of this molecule.

The incorporation of the N=C=S chemical group qualifies 4-Isothiocyanatophenyl-alpha-D-mannopyranoside as an isothiocyanate, a molecule group which frequently appears in food and medical sciences. This compound type produces an assortment of related flavors in vegetables. In coordination chemistry, isothiocyanates can operate as ligands.

4-Methoxyindole is used in a variety of preparation procedures. It is a reactant involved in the synthesis of GABA analogs, HIV-1 integrase inhibitors, anticancer agents, sodium-dependent glucose co-transporter 2 (SGLT2) inhibitors, integrase strand-transfer inhibitors (INSTIs), and isomeridianin G. Additionally, it is used in reverse-phase liquid chromatography analysis of the reaction of β-cyclodextrin and pindolol.