Triethylenediamine

Catalysis is usually accompHshed through the use of tertiary amines such as triethylenediamine. Other catalysts such as 2,4,6-/m(/V,/V-dimethylaminomethyl)phenol are used in the presence of high levels of cmde MDI to promote trimerization of the isocyanate and thus form isocyanurate ring stmctures. These groups are more thermally stable than the urethane stmcture and hence are desirable for improved flammabiUty resistance (236). Some urethane content is desirable for improved physical properties such as abrasion resistance. 

In recent years there has been some substitution of TDI by MDI derivatives. One-shot polyether processes became feasible with the advent of sufficiently powerful catalysts. For many years tertiary amines had been used with both polyesters and the newer polyethers. Examples included alkyl morpholines and triethylamine. Catalysts such as triethylenediamine ( Dabco ) and 4-dimethyla-minopyridine were rather more powerful but not satisfactory on their own. In the late 1950s organo-tin catalysts such as dibutyl tin dilaurate and stannous octoate were found to be powerful catalysts for the chain extension reactions. It was found that by use of varying combinations of a tin catayst with a tertiary amine... 

Whilst reaction can take place in the absence of catalysts it is more common to use such materials as tetra-alkylammonium halides and tertiary amines such as triethylenediamine. A major side reaction leads to the production of isocyanurate rings, particularly in the presence of tertiary amines. 

The fluoraza reagents consist of two types of compounds one in which a fluorine atom is bound to the nitrogen atom of an amide or, more often, a sulfonamide and one in which a fluorine atom is bound to the nitrogen atom of a tertiary amine such as pyridine, quinuclidine, or triethylenediamine 1,4-diaza-bicyclo[2 2.2]octane. The positive charge on the nitrogen is counterbalanced by a non-nucleophilic anion such as triflate or tetrafluoroborate. 

Parallel reactions. In water 2.4-ditrophenyl acetate (= ester) undergoes parallel hydrolysis and amination reactions (am = triethylenediamine = R NH ) according to the scheme shown. The rate constants are hyd = 2.10 X HP5 s 1 and k.m = 1.61 x... 

In a similar way, diarylthiirene dioxides can be prepared by the reaction of triethylenediamine (TED) or DABCO with a,a-dichlorobenzyl sulfones at ambient temperatures100 (equation 41). 

Triethylenediamine (DABCO) and dibutyltin dilaurate (DBTDL) have been used as catalysts with concentrations of 0.25 and 0.06Z (w/w) on binder, respectively. 

We have compared, the rate acceleration effect induced either by the CD and different moieties originated from CD, i.e quinuclidine and quinoline. These experiments were carried out in ethanol If the relative rate of racemic hydrogenation is equal to one the following relative rates has been measured quinoline = 2, quinuclidine = 3, cinchonidine = 40. In the presence of quinoline a short induction period was needed to observe the rate acceleration. It is suggested that during this period quinoline was partly hydrogenated. Other tertiary nitrogen bases, such as triethylamine, triethylenediamine, etc. resulted also rate acceleration with relative rate = 2-4. 

Activated carbon showed an auto-ignition temperature in flowing air of 452-518°C. Presence of 5% of the base ( triethylenediamine ) adsorbed on the carbon reduced the AIT to 230-260°C. At high air flow rates an exotherm was seen at 230-260°, but ignition did not then occur until 500°C. 

The reaction has been improved to a satisfactory process by modifying the reaction conditions. A remarkable effect of the addition of amines on the reaction was observed (49). For example, the reaction of butadiene (4 moles) and acetic acid (4 moles) in the presence of 2-(N,/V-dimethyl-amino)ethanol (4 moles) using Pd(acac)2 (3 mmoles) and PPh3 (3 mmoles) at 90°C gave complete conversion after 2 hours. The product was found to consist of 8-acetoxy-1,6-octadiene (47) (71%), 3-acetoxy-1,7-octadiene (48) (21%) and 1,3,7-octatriene (16) (8%). Various tertiary amines, such as triethylamine, )V-methylmorpholine, Af,Af,N, N -tetramethyl-1,3-bu-tanediamine, and triethylenediamine, showed the same favorable effect. Other basic salts, such as sodium and potassium acetate, accelerate the reaction, especially at high concentrations (50, 51). The selection of solvents is also important. Arakawa and Miyake found that electron-donating type solvents (e.g., THF and triethylamine) are good solvents... 

Triethylenediamine, d61 2,2,2-Trifluoroethyl mesylate, m453 m-T rifluoromethylphenol, t304... 

HETHYL-1-PENTENE 4-METHYL-cis-2-PENTENE 4-METHYL-trans-2-PENTENE TRIETHYLENEDIAMINE BUTYL VINYL ETHER CYCLOHEXANOL... 

METHYL-trans-2-PENTENE TRIETHYLENEDIAMINE BUTYL VINYL ETHER CYCLOHEXANOL... 

Isomerism in the Triethylenediamine Series.—Two configurations for these salts are possible, the one being the mirror image of the other, thus ... 

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