592-57-4

Basic information

• Product Name: 1,3-CYCLOHEXADIENE
• Synonyms: 1,3-CYCLOHEXADIENE;1,2-DIHYDROBENZENE;l，3-Cyclohexadiene;DIHYDROBENZENE;Cyclohexa-1,3-diene;1,3-Cyclohexadiene (stabilized with BHT);Cyclohexadiene;1,3-CYCLOHEXADIENE, STAB.
• CAS NO: 592-57-4
• Molecular Formula: C₆H₈
• Molecular Weight: 80.13
• EINECS: 209-764-1
• Product Categories: Miscellaneous;Miscellaneous Reagents
• Mol File: 592-57-4.mol

Chemical Properties

• Melting Point: -98 °C
• Boiling Point: 80 °C(lit.)
• Flash Point: −2 °F
• Appearance: Clear colorless to light yellow/Liquid
• Density: 0.841 g/mL at 25 °C(lit.)
• Vapor Pressure: 55.7mmHg at 25°C
• Refractive Index: n20/D 1.474(lit.)
• Storage Temp.: 2-8°C
• Water Solubility: Slightly miscible with methanol. Immiscible with water.
• BRN: 506024
• CAS DataBase Reference: 1,3-CYCLOHEXADIENE(CAS DataBase Reference)
• NIST Chemistry Reference: 1,3-CYCLOHEXADIENE(592-57-4)
• EPA Substance Registry System: 1,3-CYCLOHEXADIENE(592-57-4)

Safety Data

• Hazard Codes: F
• Statements: 11-10-37
• Safety Statements: 9-16-29-33
• RIDADR: UN 3295 3/PG 2
• WGK Germany: 3
• RTECS: GU4702350
• F: 9
• TSCA: Yes
• HazardClass: 3
• PackingGroup: II
• Hazardous Substances Data: 592-57-4(Hazardous Substances Data)

Usage

Uses

1. Used in Chemical Synthesis:
1,3-Cyclohexadiene is used as a key intermediate in the synthesis of various organic compounds due to its ability to undergo multiple chemical reactions. It is used as a hydrogen donor in transfer hydrogenation, facilitating the formation of carbonyl addition products with aldehydes and aromatic alcohols via iridium-catalyzed hydrogen auto-transfer and transfer hydrogenation mediated by isopropanol.
2. Used in Polymer Industry:
In the polymer industry, 1,3-Cyclohexadiene is used in living anionic polymerization with the n-BuLi/TMEDA system to form polycyclohexadiene, which has potential applications in the production of polymers with specific properties.
3. Used in Pharmaceutical Industry:
1,3-Cyclohexadiene is used in the platinum-catalyzed silaboration process to form (1R,4S)-1-(dimethylphenylsilyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-cyclohexene, which can be further utilized in the synthesis of pharmaceutical compounds.
4. Used in Research and Development:
1,3-Cyclohexadiene is useful in the study of proteomics research, where it can be employed as a reagent or a starting material for the development of new methodologies and techniques.
5. Used in Conversion to Benzene:
1,3-Cyclohexadiene is also used in the conversion to benzene, which is a fundamental building block in the chemical industry with a wide range of applications, including the production of plastics, resins, synthetic fibers, and detergents.

Preparation

1,3-Cyclohexadiene has been prepared by dehydration of cyclohexen-3-ol, by pyrolysis at 540° of the diacetate of cyclohexane-1,2-diol, by dehydrobromination with quinoline of 3-bromocyclohexene, by treating the ethyl ether of cyclohexen-3-ol with potassium bisulfate, by heating cyclohexene oxide with phthalic anhydride, by treating cyclohexane-1,2-diol with concentrated sulfuric acid, by treatment of 1,2-dibromocyclohexane with tributylamine, with sodium hydroxide in ethylene glycol, and with quinoline, and by treatment of 3,6-dibromo-cyclohexene with sodium.

Purification Methods

Distil the diene from NaBH4 or Na under N2 and collect it in a trap cooled in Dry Ice. It is highly flammable. [Marvel & Martell, J Am Chem Soc 81 450 1959, Beilstein 5 IV 382.]

InChI:InChI=1/C6H8/c1-2-4-6-5-3-1/h1-4H,5-6H2

Synthetic route

1,3,5-hexatriene (2235-12-3) → cyclohexa-1,3-diene radical cation (592-57-4) + 1,4-cyclohexadiene radical cation (628-41-1) + trans-1,3,5-hexatriene radical cation (62015-34-3) + (Z)-1,3,5-hexatriene radical cation (62015-35-4)

Conditions	Yield
In dichloromethane at -253.2℃; Irradiation; electronic spectra of the produced radical mixture; the radicals were investigated;

bicyclo{3.1.0}hex-2-ene (694-01-9) → cyclohexa-1->5-dienyl (12169-67-4) + Bicyclo<3.1.0>hex-2-ene radical (55394-12-2) + cyclohexa-1,3-diene radical cation (592-57-4) + Bicyclo<3.1.0>hex-2-ene radical cation (694-01-9, 126110-24-5)

Conditions	Yield
In 1,1,2-Trichloro-1,2,2-trifluoroethane Mechanism; Irradiation; 1) 77 K, 2) 130 K; also in CCl3F;

cyclohexa-1,4-diene (1165952-92-0) → cyclohexa-1,3-diene radical cation (592-57-4) + 1,4-cyclohexadiene radical cation (628-41-1) + trans-1,3,5-hexatriene radical cation (62015-34-3) + (Z)-1,3,5-hexatriene radical cation (62015-35-4)

Conditions	Yield
In dichloromethane at -253.2℃; Irradiation; electronic spectra of the produced radical mixture; the radicals were investigated;

cyclohexa-1,3-diene (1165952-91-9) → cyclohexa-1,3-diene radical cation (592-57-4) + 1,4-cyclohexadiene radical cation (628-41-1) + trans-1,3,5-hexatriene radical cation (62015-34-3) + (Z)-1,3,5-hexatriene radical cation (62015-35-4)

Conditions	Yield
In dichloromethane at -253.2℃; Irradiation; electronic spectra of the produced radical mixture; the radicals were investigated;

Upstream product

• 2699-13-0 3-methoxycyclohexene 
• 1165952-92-0 cyclohexa-1,4-diene 
• 1165952-91-9 cyclohexa-1,3-diene 
• 694-01-9 bicyclo{3.1.0}hex-2-ene 
• 2235-12-3 1,3,5-hexatriene 

Relevant articles and documents

ESR study of radical cations from γ-irradiation of bicyclo[3.1.0]hex-2-ene in freon matrices

Bicyclo[3.1.0]hex-2-ene radical cation, generated by γ-irradiation of the parent compounds in freon matrices at 77 K, undergoes ring opening to the 1,3-cyclohexadiene radical cation, In CF2ClCFCl2 matrix both radical cations also undergo deprotonation to the corresponding neutral radicals.

The gas-phase elimination reaction of 3-methoxycyclohexene: Regiochemistry

Gas-phase elimination reactions of deuterium labeled 3-methoxycyclohexenes have been investigated. 1,4-Elimination is heavily favored over 1,2-elimination when strong bases such as hydroxide and amide are used. The 1,2-pathway becomes more competitive when weaker bases such as methoxide are employed, and the mechanism shifts from E1 cB to E2.

Photochemical Rearrangements of C6H8, C7H10, and C8H12 Radical Cations in Solid Argon at 20 K

C6H8 radical cations have been produced by matrix photoionization techniques and trapped in solid argon.Electronic spectra show that two different types of products are formed; a conjugated diene cation with strong and weak absorption between 30000 and 20000 cm-1 and conjugated triene cations with a strong absorption between 28000 and 22000 cm-1 and weak absorptions between 18000 and 14000 cm-1.With selective photolysis in the high-energy bands, the conjugated triene cation geometric isomers were interconverted while the cyclic diene cations were ring opened to give conjugated triene cations.Similar experiments with cyclic and bicyclic C7H10 cations gave three conjugated heptatriene cation conformers, and cyclic C8H12 cations yielded a number of conjugated octatriene cation isomers.