1,2-Diaminocyclohexane - commonly abbreviated DACH and also called 1,2-cyclohexanediamine or DCH-99 - is one of the most useful aliphatic diamines in fine-chemical and electronic-chemical manufacturing. With the molecular formula C₆H₁₄N₂ and CAS 694-83-7, this single molecule powers everything from high-performance epoxy systems to the chiral catalysts behind modern drug synthesis. ✅

This guide is the starting point for our complete DACH knowledge series. Below you will find a clear answer to "what is 1,2-diaminocyclohexane," a look at its three stereoisomers, its key properties, how it is produced, and the industrial and pharmaceutical applications that make it a strategic raw material.

🔬 What Is 1,2-Diaminocyclohexane?

1,2-Diaminocyclohexane is a primary aliphatic diamine built on a saturated six-membered cyclohexane ring, with two amino (–NH₂) groups attached to adjacent carbon atoms. That simple "1,2" arrangement of two reactive amine groups is exactly what makes the molecule so valuable: it can bridge, chelate, cross-link, and coordinate, giving chemists a compact, rigid backbone for building far more complex molecules. 💡

The commercial product is usually a mixture of three stereoisomers - the cis form plus both enantiomers of the trans form - and presents as a colorless, corrosive liquid that can turn pale yellow with age. Because the two amine groups sit on neighboring carbons, DACH behaves as a strong base and reacts readily with acids, anhydrides, epoxides, and aldehydes.

🏷️ Names, Synonyms & Identifiers

DACH appears under many trade and catalog names. The most common include:

• ✅ 1,2-Cyclohexanediamine - the IUPAC-style synonym
• ✅ DACH - the standard industrial abbreviation
• ✅ DCH-99 - a common commercial grade designation
• ✅ Cyclohexane-1,2-diamine - the preferred IUPAC name

For procurement and regulatory work, always confirm the exact CAS number, because the isomer matters: 694-83-7 denotes the mixed isomer material, 1121-22-8 the racemic trans form, while the single enantiomers (1R,2R) and (1S,2S) carry their own CAS numbers used in chiral synthesis.

🧬 The Three Stereoisomers of DACH

Stereochemistry is central to understanding 1,2-diaminocyclohexane. Because each of the two ring carbons bearing an –NH₂ group is a stereocenter, DACH exists as a cis isomer and a pair of trans enantiomers - (1R,2R) and (1S,2S). The trans enantiomers are the prized building blocks for chiral ligands, and they can be separated using tartaric acid as a resolving agent. 🔬

For a full breakdown of cis vs trans, chirality, and which isomer to specify for your application, see our dedicated guide on cis vs trans 1,2-diaminocyclohexane isomers and chirality, and the companion guide on

resolving trans-DACH with tartaric acid.

📊 Key Physical & Chemical Properties

At a glance, the headline properties of 1,2-diaminocyclohexane are:

Need exact figures for density, molecular weight, boiling and melting points, or solubility? Our detailed reference covers them all in our article on 1,2-diaminocyclohexane properties, and the

structure, formula and NMR guide explains the molecule's geometry.

🏭 How DACH Is Manufactured

The dominant commercial route to 1,2-diaminocyclohexane is the catalytic hydrogenation of o-phenylenediamine, which saturates the aromatic ring to deliver the mixed-isomer diamine. DACH also arises as a side product during the hydrogenation of adiponitrile. The full process - feedstocks, catalysts, and how isomer ratios are controlled - is covered in our article on how 1,2-diaminocyclohexane is made. 💡

🚀 Main Applications of 1,2-Diaminocyclohexane

DACH's reactive twin amine groups make it a workhorse across four major fields:

⚠️ Safety Essentials

1,2-Diaminocyclohexane is classified as corrosive (signal word: Danger). It can cause severe skin burns and eye damage, may cause an allergic skin reaction, and is harmful if swallowed, inhaled, or in contact with skin. Always handle with appropriate PPE in a well-ventilated area. Full handling, storage, and transport (UN 2735) guidance is in our DACH hazards & SDS guide. 🧤

❓ Frequently Asked Questions

🔹 What is 1,2-diaminocyclohexane used for?

It is mainly used as an epoxy curing agent, a chiral ligand building block for asymmetric catalysis, a precursor to CDTA chelating agents, and an intermediate for platinum-based pharmaceuticals such as oxaliplatin.

🔹 What is the CAS number of DACH?

The mixed-isomer material is CAS 694-83-7. The racemic trans form is CAS 1121-22-8, and the single (1R,2R) and (1S,2S) enantiomers carry their own CAS numbers.

🔹 Is DACH the same as 1,2-cyclohexanediamine?

Yes. DACH, 1,2-diaminocyclohexane, 1,2-cyclohexanediamine, and DCH-99 all refer to the same compound, C₆H₁₄N₂.

🔹 Is 1,2-diaminocyclohexane hazardous?

Yes. It is corrosive and can cause skin burns and eye damage, and may trigger skin sensitization. Use proper PPE and consult the SDS before handling.

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