1,5-Dimethylhexylamine CAS 543-82-8

Melting point 25 ° C, Boiling point 154-156 ° C (lit.), Density 0.767 g / ml at 25 ° C (lit.), Refractive index N20 / D 1.422 (lit.), Flash point 120 ° f, Storage conditions flammables area, Acidity coefficient (PKA) PKA 10.28 ± 0.1 (H2O, t = 25 ± 0.2, I < 0.001) (uncertain), Form liquid.

This method is a classic synthesis method for DMHA. The reaction raw materials of this method mainly include 1-methylcyclohexylamine, dimethyl succinate, sulfuric acid, aluminum trichloride, hydrogen chloride, etc.

The specific reaction process is as follows: firstly, dimethyl succinate and 1-methylcyclohexylamine undergo cyclization reaction under the catalysis of sulfuric acid and aluminum trichloride to obtain 1,5-dimethylcyclohexanone.

Then, 1,5-dimethylcyclooctanone is oxidized to the corresponding keto acid transition state compound by using alkaline oxidant such as sodium hydroxide.

Finally, the target product it is obtained by hydrolysis in hydrogen chloride or acetic acid. This method is convenient for synthesis, with high reaction efficiency and a yield of over 80%.

This method uses 2-pentanone as the raw material, generates 1,5-cyclohexanedione through the Kreiss cyclization reaction, and converts it to it through reduction.

The reaction raw materials mainly include 2-pentanone, dimethyl succinate, aluminum trichloride, tetrahydrofuran, etc. The reaction process is as follows: first, dimethyl succinate is reacted with aluminum trichloride to obtain the corresponding dextral methyl succinate.

After heating treatment, it is decarboxylated to form 2-pentanone; Then, 2-pentanone is reacted with tetrahydrofuran and aluminum trichloride to undergo the Kreiss cyclization reaction, resulting in 1,5-cyclohexanedione.

Finally, the target product DMHA was obtained through hydrogenation reaction. The step-by-step operation of this method is cumbersome, but the reaction conditions are mild, the applicability is wide, and the yield is high.

1,5-Dimethylhexan-1-amine is a typical branched aliphatic primary amine. Its overall chemical properties are governed by the terminal amino group (–NH₂), while its carbon skeleton consists of saturated branched alkyl moieties with relatively high chemical inertness, resisting cleavage, rearrangement and other transformations under ordinary conditions.

This compound exhibits pronounced organic basicity; the pKa of its conjugate acid is approximately 10.28 at 25 °C. Upon slight dissolution in water, a proton dissociation equilibrium is established, rendering the aqueous solution distinctly alkaline. It can induce color shifts in conventional acid-base indicators and undergoes neutralization reactions with acidic substances.

The nitrogen atom of the amino group carries a lone pair of electrons and demonstrates excellent nucleophilic reactivity, constituting the principal reactive site of the molecule. It undergoes protonation and neutralization with mineral acids including hydrochloric acid and sulfuric acid, as well as carboxylic organic acids, yielding ammonium salts featuring superior stability and aqueous solubility.

Among these salts, the hydrochloride and sulfate possess favorable crystallinity and are routinely utilized for the purification, isolation and structural characterization of the parent amine.

Meanwhile, the amino group participates in nucleophilic substitution reactions with common acylating agents such as acid chlorides and acid anhydrides to form stable amide derivatives. It also undergoes stepwise N-alkylation with alkyl halides, sequentially generating secondary amines, tertiary amines and even quaternary ammonium salts, representing its major derivatization pathways.

This compound possesses moderate chemical stability at ambient temperature. When stored in an open vessel, it is susceptible to slow oxidative degradation triggered by oxygen and moisture present in ambient air, accompanied by gradual darkening of the liquid and formation of trace oxidative impurities.

Sealed air-excluding storage is therefore mandatory. It bears no risk of spontaneous polymerization, and its saturated alkyl skeleton confers substantial reaction inertness, allowing the compound to remain largely intact under mild reaction conditions.

Nevertheless, classified as a flammable alkaline amine, it must never be stored or mixed with strong oxidants or concentrated strong acids. Contact with these substances readily initiates highly exothermic oxidative decomposition reactions that create significant safety hazards. Strict segregated storage and standardized handling protocols must be enforced during industrial and laboratory operations.