2556-36-7

Basic information

• Product Name: cyclohex-1,4-ylene diisocyanate
• Synonyms: cyclohex-1,4-ylene diisocyanate;1,4-diisocyanatocyclohexane;cyclohexane diisocyanate;CYCLOHEXANE,1,4-DIISOCYANATO-;1,4-cyclohexylene diisocyanate;(1,4-Cyclohexanediyl)bisisocyanate;(1,4-Cyclohexanediyl)diisocyanate;Cyclohexane-1,4-diylbisisocyanate
• CAS NO: 2556-36-7
• Molecular Formula: C₈H₁₀N₂O₂
• Molecular Weight: 166.1772
• EINECS: 219-869-4
• Mol File: 2556-36-7.mol
• Article Data: 1

Chemical Properties

• Melting Point: 55℃
• Boiling Point: 136℃ (15 Torr)
• Flash Point: 94.7°C
• Appearance: /
• Density: 1.21g/cm³
• Vapor Pressure: 0.0368mmHg at 25°C
• Refractive Index: 1.567
• CAS DataBase Reference: cyclohex-1,4-ylene diisocyanate(CAS DataBase Reference)
• NIST Chemistry Reference: cyclohex-1,4-ylene diisocyanate(2556-36-7)
• EPA Substance Registry System: cyclohex-1,4-ylene diisocyanate(2556-36-7)

Safety Data

• RIDADR: 2922
• HazardClass: 8
• PackingGroup: II
• Hazardous Substances Data: 2556-36-7(Hazardous Substances Data)

Usage

Uses

Used in Flame Retardant Applications:
Cyclohex-1,4-ylene diisocyanate is used as a reagent for the synthesis of flame retardants, particularly those based upon polyurethane. Its application in this field is due to its ability to form stable and fire-resistant polymers when reacted with other compounds, providing enhanced safety and durability in various materials.
Used in Environmental Regulation:
Cyclohex-1,4-ylene diisocyanate is recognized as an environmental toxin and is listed on the US EPA Toxic Release Inventory (TRI) list. This classification highlights the need for proper handling, storage, and disposal of the compound to minimize its potential impact on human health and the environment. The listing also promotes research and development of safer alternatives and improved industrial processes to reduce the release of this toxic substance into the environment.

Reactivity Profile

Isocyanates and thioisocyanates, such as cyclohex-1,4-ylene diisocyanate, are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence, [Wischmeyer(1969)].

InChI:InChI=1/C8H10N2O2/c11-5-9-7-1-2-8(4-3-7)10-6-12/h7-8H,1-4H2

Synthetic route

trans-1,4-diaminocyclohexane (3114-70-3) → 1,4-cyclohexane diisocyanate (2556-36-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: 1,2-dichloro-benzene / 2 h / 60 °C 2: 1,2-dichloro-benzene / 3 h / 140 °C / 760.05 Torr View Scheme

C8H12F2N2O2 → 1,4-cyclohexane diisocyanate (2556-36-7)

Conditions	Yield
In 1,2-dichloro-benzene at 140℃; under 760.051 Torr; for 3h; Concentration;

bis(tetrabutylammonium) hexamolybdate + 1,4-cyclohexane diisocyanate (2556-36-7) → 4(C4H9)4N(1+)*Mo6O18NC6H10NMo6O18(4-)=[(C4H9)4N]4Mo6O18NC6H10NMo6O18

Conditions	Yield
In pyridine (N2); stirring 3 d at 25°C; evapn., washing (CH2Cl2), drying (vac.);	80%

1,4-cyclohexane diisocyanate (2556-36-7) → Cyclohexan-1,4-bis (10372-96-0)

Conditions	Yield
With chlorine In chloroform

Cyclopentanol (96-41-3) + 1,4-cyclohexane diisocyanate (2556-36-7) → (4-Cyclopentyloxycarbonylamino-cyclohexyl)-carbamic acid cyclopentyl ester

Conditions	Yield
In toluene at 55℃; Rate constant;
dibutyltin bis(2-ethylhexanoate) In toluene at 55℃; Rate constant;

9-[(1R,2S,3R,4S)-2,3-dihydroxy-4-(2-hydroxy-acetylamino)-cyclopentyl]-6-((S)-1-hydroxymethyl-2-phenyl-ethylamino)-9H-purine-2-carboxylic acid (2-amino-ethyl)-amide (1056938-68-1) + 1,4-cyclohexane diisocyanate (2556-36-7) → C56H74N18O14

Conditions	Yield
In tetrahydrofuran at 20℃; for 72h;

nitroacetic acid ethyl ester (626-35-7) + 1,4-cyclohexane diisocyanate (2556-36-7) → C16H24N4O10 (391894-61-4)

1,4-cyclohexane diisocyanate (2556-36-7) + C20H33NO5 → C48H76N4O12

Conditions	Yield
With trimethylamine In toluene

1,4-cyclohexane diisocyanate (2556-36-7) + C20H34N2O4 → C48H78N6O10

Conditions	Yield
With trimethylamine In toluene

1,4-cyclohexane diisocyanate (2556-36-7) → C48H68Cl2N18O8

Conditions	Yield
Multi-step reaction with 4 steps 1: trimethylamine / toluene 2: hydrogenchloride / 1,4-dioxane 3: N-ethyl-N,N-diisopropylamine / ethanol 4: hydrogenchloride / 1,4-dioxane View Scheme

1,4-cyclohexane diisocyanate (2556-36-7) → C36H58N6O6*(x)ClH

Conditions	Yield
Multi-step reaction with 2 steps 1: trimethylamine / toluene 2: hydrogenchloride / 1,4-dioxane View Scheme

1,4-cyclohexane diisocyanate (2556-36-7) → C60H88Cl2N18O12

Conditions	Yield
Multi-step reaction with 3 steps 1: trimethylamine / toluene 2: hydrogenchloride / 1,4-dioxane 3: N-ethyl-N,N-diisopropylamine / ethanol View Scheme

Upstream product

• 3114-70-3 trans-1,4-diaminocyclohexane 

Downstream Products

• 391894-61-4 C₁₆H₂₄N₄O₁₀ 
• 10372-96-0 Cyclohexan-1,4-bis 

Relevant articles and documents

Method for preparing isocyanate by using amine and carbonyl fluoride

The invention discloses an efficient synthesis method for preparing corresponding isocyanate by enabling carbonyl fluoride to directly react with amine. The efficient synthesis method mainly comprises the following two steps: carrying out acylation reaction on the amine and the carbonyl fluoride according to a preferable proportion in an anhydrous inertial organic solvent under a sealed environment and a proper reaction condition, thus generating an intermediate-carbamyl fluoride; (2) carrying out dehydrofluorination on the intermediate-carbamyl fluoride under normal pressure and the proper reaction condition, thus obtaining the target isocyanate. During a reaction process, addition of a catalyst is not needed, the reaction conditions are mild, excessive carbonyl fluoride and a used solvent during the reaction process can be efficiently recycled and reused, and a by-product HF can be commercially sold after being collected and refined.