Diethanolamine hydrolysis

To effectively remove carbonyl sulfide from a gas stream, special alkaline scmbbiag Hquors are used. These contain sodium aluminate or sodium plumbite, or they are made of alkaUes with a hydrolysis catalyst based on Zn, Fe, Ni, or Cu. Diethanolamine, diglycolamine, or other alkanolamines (qv) mixed with water remove carbonyl sulfide from sour, ie, acid-gas-containing, gas streams (25,26) (see Carbon dioxide). 

A modification of the WiUgcrodt reaction that simplifies the procedure by obviating the necessity of a sealed tube 01 autoclave consists in refluxing the ketone with a high-boiling amine and sulfur (Schwenk, 1942). Morpholine, so named because of a relationship to an early erroneous partial formula suggested for morphine, is suitable and is made technically by dehydration of diethanolamine. The reaction is conducted in the absence of water, and the reaction product is not the amide but the thioamide this, however, undergoes hydrolysis in the same manner to the arylacetic acid. 

Cyclic boric acid esters derived from triethanolamine (Figure 9.11) or diethanolamine can be stabilized toward hydrolysis by an intramolecular, boron-nitrogen coordination bonding. The blockage of the empty-orbital on the boron atom can alleviate hydrolysis. This effect has been used to prepare... 

Lemire et al. (32) reported a quantitative method for the determination of IV-ethyl- and A-methyldi-ethanolamine, the hydrolysis products of HN-1 and HN-2, in urine using LC/ESI/MS/MS on a triple sector quadrupole instrument. The analytes were concentrated from urine by SPE on a strong cation exchanger. In order to obtain good peak shapes, 73% 3mM ammonium hydroxide (pH 10.5) - 27 % methanol was used as the mobile phase for LC. Isotope dilution ([13C]4-/V-Me and N-Et diethanolamines) was used to compensate for inherent variabilities. Detection was by MRM, monitoring the transition MH+ —> [MH-H20]+ for each analyte. The limits of detection were 0.4 ng/ml for V-ethyldiethanolaminc and 1 ng/ml for N-methyldiethanolamine. An interferent was present in urine with similar retention time and nominal mass characteristics as /V-mclhyldiclhanolaminc. 

APases hydrolyze numerous phosphate esters, such as those of primary and secondary alcohols, phenols and amines (Levine, 1974). One unit of activity of APase corresponds to the hydrolysis of 1.0 pmole of p-nitrophenyl phosphate (p-NPP) per min (in 100 mM glycine, 1 mM ZnCb, 1 mM MgCl2 and 6 mM p-NPP, pH 10.4 or in 1 M diethanolamine, 0.5 mM MgCU and 15 mM p-NPP, pH 9.8). The bovine enzyme generally has a specific activity of 1000 and 2000 U/mg in these two buffers, respectively, at 37°C. At 25°C, activity is reduced to about half. This demonstrates that buffers may have a marked influence on the enzymatic activity of APases which explains the great differences in activity given for commercial preparations. Assays with p-NPP above 30°C suffer from the spontaneous hydrolysis of this substrate, with serious consequences for the enzyme kinetics (see below). The bacterial enzyme has lower activity than the bovine intestinal enzyme. 

Fig. 6 The catalytic mechanism of the alkaline phosphatase reaction. The initial alkaline phosphatase (E)-catalyzed reaction consists of a substrate (DO-Pi) binding step, phosphate-moiety transfer to Ser-93 (in the TNAP sequence of its active site), and product alcohol (DOH) release. In the second step of the reaction, phosphate is released through hydrolysis of the covalent intermediate (E-Pi) and the non-covalent complex (E Pi) of the inorganic phosphate in the active site. In the presence of nitrogen-containing alcohol molecules (AOH), such as the buffer diethanolamine (DEA), phosphate is also released via a transphosphorylation reaction...

Alkanolamine Condensates, Alkanolamides Mainly of diethanolamine or monoisopropanolamine. Good stability to hydrolysis by hot alkali, poor-fair stability to hot acids. 

The glycolysis of urea groups takes place at a lower reaction rate than the glycolysis of urethane groups. The catalysts for both reactions, glycolysis and hydrolysis are alkali hydroxides (NaOH, KOH, LiOH) [11, 12, 25, 26, 30, 31], diethanolamine[ll, 26] and some titanium or tin compounds. One of the best catalysts is LiOH [11]. 

Similarly, a recent patent combines aminolysis and hydrolysis reactions for achieving polyurethane decomposition.98 Thus, scrap polyurethane is reacted with a mixture of diethanolamine and aqueous sodium hydroxide. The simultaneous attack of these agents on the polymeric chains allows the reaction time to be appreciably shortened. The reaction product, obtained as an emulsion, is subjected to a second treatment with propylene oxide in order to transform the amines and ureas present in the mixture into polyols, giving a final product which is substantially free of any hydrogen-containing nitrogen atoms. The polyols produced have been found to be particularly suitable for the preparation of fresh polyurethane polymer which can be used as an elastomer or flexible foam. 

Functional alcohols, such as alcoxyalcohols—mainly 2-methoxyethanol—or alkanolamines (diethanolamine and triethanolamine), are actually the most commonly used to slow hydrolysis rates and thus to stabilize metal alkoxides. Although such exchange reactions occur at room temperature, some heat-... 

The oil phase consisted of 36 g of kerosene with 530 wt% of surfactant. The surfactant was sorbitan monooleate (Span 80 ) and sorbitan monostearate (Span 60 ) with a weight ratio of Span 80 /Span 60 = 3 1. The water phase consisted of TTIP, diethanolamine, methanol and water. DEA was used as a stabilizer to control the hydrolysis rate of TTIP, and methanol was used to increase the compatibility between water and TTIP. The molar ratio of... 

Monomeric herbicides of diethanolamine derivatives were also prepared, followed by melt polycondensations with dicarboxylic acids to give the corresponding herbicide polyesters (Scheme 3.14) [139]. Solution polycondensation was used in the synthesis of the herbicide-polyurethane derivatives by the reaction of diethanolamine derivatives with HMDI. The linear polymers were crosslinked by reaction with HMDI (5, 10 %) to afford swellable polymeric materials. The preformed amine-containing polyester was also modified with 2,4-D. The hydrolysis rate of 2,4-D from the polymers was measured under different simulated conditions. 

Occasionally it is found that an additive that has been extracted from a plastic will undergo a chemical change upon reaction with the extract. A case in point is that of the antistatic additive lauric diethanolamide which upon reaction with aqueous extraction liquids is hydrolysed to diethanolamine and lauric acid. In these circumstances it is not only the toxicity of lauric diethanolamide that must be considered but also that of the two hydrolysis products. In fact, it has been ascertained that during a 14 day extraction test on PP carried out at 60 "C some 100% of the extracted diethanolamide is hydrolysed ... 

The synthetic route to iV-aryl [3.2.2] cryptands 5a and 5b is shown in the Scheme. Starting from the A-aryl diethanolamine, reaction with two equivalents of chloro-acetic and /-BuOK in t-BuOH followed by conversion of the diacid to the diester for purification gave la and lb in yields of 49 and 25%, respectively. Subsequent acid-catalyzed hydrolysis produced the dicarboxylic acid amine hydrochlorides 2a and 2b quantitatively. Attempts to form the diacid chloride of 2a resulted in an unreactive deep blue-colored substance of unknown identity. Ring closure was effected by adaptation of a method from peptide synthesis [8]. Mixed anhydrides 3a and 3b formed by reaction with two equivalents of isobutyl chloroformate in the presence of triethylamine were cyclized with l,10-diaza-18-crown-6 in toluene to produce the corresponding cryptand diamides 4a and 4b in 36 and 32% yields, respectively. Reduction with borane-dimethyl sulfide in THF provided 74% yields of 5a and 5b. 

The official sulphonamides are all derivatives of sulphanilamide and the assay for all members of the group by diazotisation follows that of the parent substance either directly or after preliminary hydrolysis or reduction (para-nitrosulphathiazole) except for sulphafurazole and sulphafurazole diethanolamine. Sulphafurazole cannot be diazotised quantitatively since the product consumes more than one equivalent of nitrous acid. Non-aqueous titration can also be applied. 

For conventional amine absorption processes, the amines used (monoethanolamine, diethanolamine, dimethy-lamine, etc.) are unhindered a hindered amine has a bulky alkyl group attached to the amino group as in Figure 5.2.1 (Sartori et al., 1987). The carbamates of such hindered amines are much less stable than the carbamates of the corresponding unhindered amines. For example, the equilibrium constant for the hydrolysis reaction (5.2.18a),... 

In commercial plants all of the carbonyl sulfide present in the feed gas does not react with monoethanolamine. Pearce et al. (1%1) and Berlie et al. (1965) report that the major portion of the CX>S undergoes hydrolysis, forming H2S and CO2, and only about 15 to 20% of the COS reacts irreversibly with the monethanolamine. The addition of strong alkalis, such as sodium carbonate or sodium hydroxide, to monoethanolamine solutions reduces losses due to reaction with COS substantially, probably by increasing tiie rate of COS hydrolysis (Pearce et al., 1961). Although monoetiianolamine losses can be reduced by this method, use of diethanolamine is preferred if the gas to be treated contains appreciable amounts of COS. 

The weight of lauric diethanolamide (0.0080 g) taken would, upon complete hydrolysis yield 0.0029 g diethanolamine. The fact that this weight of DEA was obtained in the column effluent indicated that lauric diethanolamide is completely hydrolysed by 5% citric acid during 10 days at 60 i.e., the sulfuric acid... 

The preparation of functionalized aryl boronic reagents can be achieved by directed metallation followed by a transmetallation of aryllithiums with organoboron compounds. Thus, Caron and Hawkins have described a directed ortho-metalla-tion of aryl neopentyl esters such as 1 for the synthesis of substituted ortho-horo-nyl neopentyl benzoates using lithium diisopropylamide (LDA) as the base and B(OiPr)3 as an in situ trap [3]. The crude boronic acids obtained by acidic hydrolysis were subsequently treated with ethanolamine and converted to stable diethanolamine complexes such as 2. This methodology allows the preparation of a new class of boronic acids with ortho-carbonyl substituents and other functionalities... 

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