Triethylenediamine CAS NO.280-57-9

Introduction

Triethylenediamine, also known as 1,4-diazabicyclo[2.2.2]octane, or triethylenediamine, abbreviated as DABCO or TEDA, has the chemical formula C6H12N2. It is a very important and highly efficient catalyst in chemical production and is widely used in condensation reactions, polyurethane foaming catalysis, pesticide synthesis, and electroplating. Thanks to its highly symmetrical and compact chemical structure, TEDA is widely used in many fields.

Applications
Triethylenediamine (DBACO) is an important chemical raw material, used as a catalyst for polyurethanes and as an oil additive; it is used as a corrosion inhibitor in boiler water treatment, as a catalyst for polyurethane foaming and polymerization, as an accelerator for epoxy resin curing, and as a catalyst for acrylonitrile, ethylene, and alkylethylene oxides; as a non-nucleophilic base, it is a reagent for the cleavage of β-keto esters and geminal diesters and for dehydrohalogenation reactions; it forms complexes with organomagnesium, lithium, and zinc compounds to increase its activity and participate in many reactions.

Preparation

(1) Piperazine was dissolved in methanol beforehand. 123.9 g (1.05 mol) of dimethyl oxalate was added to a reaction flask equipped with a mechanical stirrer. Methanol was added until completely dissolved. 4.3 g of sodium methoxide was added. Then, 86 g (1 mol) of piperazine dissolved in methanol was slowly added dropwise at 40 °C. After adding dropwise, the mixture was stirred for 1-2 hours and then filtered. The resulting filter cake was washed with methanol and dried to obtain the intermediate product triethylenediamine dioxide. (2) Triethylenediamine dioxide prepared in step (1) was added to a high-pressure reactor. Tetrahydrofuran was added. Add 4.3g of palladium on carbon to the furan until completely dissolved, seal the reactor tightly, heat to 175℃, and purge hydrogen into the high-pressure valve until the pressure reaches 5MPa. Continue purging with hydrogen during the reaction to maintain the pressure until it no longer drops significantly, yielding crude triethylenediamine. (3) Open the exhaust valve of the high-pressure reactor to vent the gas, open the reactor lid, and cool to room temperature. Filter the crude triethylenediamine obtained in step (2) to remove the catalyst, distill off tetrahydrofuran, add ethanol to slurry, filter, and dry the resulting filter cake to obtain 98.11g of the final product, triethylenediamine. The molar yield of triethylenediamine was calculated to be 87.6%, and the purity of triethylenediamine was 99.0% as determined by gas chromatography.

Chemical Properties

The anhydrous form is a flammable white crystalline solid, extremely deliquescent. It is soluble in water, ethanol, acetone, and benzene. Its solubility at 25℃ is 45g/100g in water, 77g/100g in ethanol, 13g/100g in acetone, and 51g/100g in benzene.

Applications
It can be used in the production of various products such as polyurethane foams, elastomers, and coatings. It is also used as a catalyst and petroleum additive in the production of polyurethane foam plastics.