1,3-Indandione TCI I0012

1,3-Indandione is a cyclic diketone built on the indane skeleton, in which a benzene ring is fused to a five-membered ring carrying two carbonyl groups at positions 1 and 3. In the organic synthesis laboratory, this compound serves as a highly versatile non-heterocyclic building block, largely because the carbon atom at position 2 sits directly between two carbonyl groups. That arrangement turns position 2 into an active methylene centre that is readily deprotonated and carried forward into further reactions, allowing researchers to construct a wide range of substituted indandione derivatives from a single common starting material.

The characteristic that makes this material a preferred choice is the acidity of the proton at position 2, which is far higher than that of an ordinary ketone because the resulting anion is stabilised by resonance across both carbonyl groups as well as the aromatic ring. This property opens the way to Knoevenagel condensation with aldehydes, Michael addition, and the construction of conjugated donor–acceptor chromophore systems. Its physical form is a crystalline solid that is straightforward to weigh and transfer, while adequate solubility in polar organic solvents such as ethanol, acetonitrile, and dichloromethane simplifies the preparation of working solutions.

In Indonesian laboratories, 1,3-indandione is typically used in university and institutional organic synthesis groups, in materials chemistry work directed at conjugated dye systems, and in method development that requires a dependable active methylene reagent. Because it is supplied as an easily handled crystalline solid with a defined structural role, it fits well into routine bench-scale preparations, teaching laboratories running condensation experiments, and research programmes building libraries of substituted indandione derivatives.

• Knoevenagel condensation with aldehydes — the strongly acidic methylene position at C-2 condenses readily with a wide range of aldehydes, giving access to arylidene indandione products from a single reagent.
• Michael addition chemistry — the stabilised carbanion generated at position 2 acts as a reliable nucleophile towards acceptors, allowing researchers to extend the indandione core with new carbon substituents.
• Synthesis of donor–acceptor chromophores — the two carbonyl groups make the indandione unit a strong acceptor, so it is widely used to build conjugated push–pull systems for materials chemistry studies.
• Preparation of substituted indandione derivative libraries — a single common starting material can be elaborated at position 2 in many directions, which suits screening work and structure–activity exploration in research groups.
• Teaching and method development in organic synthesis — the crystalline form is easy to weigh and transfer, and its predictable active methylene reactivity makes it a dependable substrate for demonstrating condensation reactions.

• Catalogue code: I0012

Store 1,3-indandione in its original tightly closed container in a cool, dry, well-ventilated place, protected from light and kept away from strong oxidising agents and sources of ignition. Amber glass or the supplier's original packaging is suitable, and containers should be resealed promptly after each use to limit exposure to atmospheric moisture. Handle the solid in a fume hood using gloves, safety glasses, and a laboratory coat, and avoid generating or inhaling dust during weighing and transfer. Use clean, dry spatulas to prevent contamination of the stock, wash hands after handling, and consult the supplier's safety data sheet before first use and before disposal of any residues.

—