Hydrolysis during

Cannot be used for alcohols, phenols or amines, with all of which it combines. Not advisable for acidic liquids, as ordinary calcium chloride always contains some calcium hydroxide owing to partial hydrolysis during preparation. Usually used for alcohols (see p. 88). Cannot be used for acidic compounds, nor for esters, which it would hydrolyse. 

Ergonovine (100, R = NHCH(CH3)CH2 0H) was found to yield lysergic acid (100, R = OH) and (+)-2-aminopropanol on alkaline hydrolysis during the early analysis of its stmcture (66) and these two components can be recombined to regenerate the alkaloid. Salts of ergonovine with, for example, malic acid are apparently the dmgs of choice in the control and treatment of postpartum hemorrhage. 

A reactive dye—cellulose bond is subject to some slight hydrolysis during washing under alkaline conditions. 

Tria2inyl reactive dyes show less tendency toward hydrolysis during washing than do the vinyl sulfone type. 

Small amounts of the volatile amine are lost by hydrolysis during the evaporation and recrystallization of the salt. 

The propionitrile (94) also yielded a pyrido[2,3-d]pyTimidine (96) when treated with ammonia or methylamine, the intermediate amidine (95) undergoing hydrolysis during the reaction.Amination was shown to be the rate-determining stage. 

The function of the carbon coating is to contain the byproducts of the fission reaction, thereby reducing the shielding requirements. It also protects the nuclear fuel from embrittlement and corrosive attack and from hydrolysis during subsequent processing steps. CVD coatings of alumina deposited at 1000°C and beryllia deposited at 1400°C have also been studied for that purpose.P l... 

The medium is most often acidihed with hydrochloric acid (0.1% vNY but it should be noted that in light of the work of Revilla et al., the hydrochloric acid concentration should not exceed 0.12 mole/liter to prevent risks of anthocyanidin hydrolysis. Formic acid (2% v/v), with a greater volatility than hydrochloric acid, is preferred because it prevents risks of hydrolysis during the extract concentration stage. ... 

Here two components, the free phenol and the intact ester, are included in the residue definition. Usually, analytical methods for the determination of bromoxynil and its octanoate begin with hydrolysis during maceration of the sample. If those methods are validated, the sole fortification of the octanoate is sufficient. However, in other existing methods, hydrolysis follows a separate extraction step. In that case, the chosen solvent must be able to extract both compounds with equal efficiency. 

Aldehydes can also be obtained from Grignard reagents by reaction with formamides, such as A-formylpiperidine. In this case, the initial adducts are stable and the aldehyde is not formed until hydrolysis during workup. 

The di-t-butyl-substituted silanols 40 and 41 result from hydrolysis during column chromatography of the corresponding triflates and have also been structurally characterized (240). The adamantyl compound... 

As may be seen from Table 3.22, MTBE does not extract additives from PA6, as opposed to dissolution in the expensive solvent HFIP. It is also evident that in these conditions intact Ultranox 626 is not observed the hydrolysis product 2,4-di-f-butylphenol (2,4-DTBP) is observed instead. 31P NMR confirms hydrolysis of Ultranox 626. The results do not discriminate between hydrolysis during mixing or analysis. As also SFE does not detect Ultranox 626 hydrolysis is likely to occur in the mixing step. Dissolution with HFIP and SFE (after optimisation) give identical results. In this case the added value of SFE extraction consists in a considerable cost reduction. 

Dissolve the protein or peptide to be thiolated at a concentration of lOmg/ml in 50 mM sodium phosphate, pH 7.5, containing 1 mM EDTA. Other non-amine containing buffers such as borate, HEPES, and bicarbonate also may be used as the reaction medium. The effective pH for the NHS ester modification reaction is in the range of 7.0-9.0. Conditions closer to neutral pH will limit the degree of NHS ester hydrolysis during the reaction. 

A new generation of cheap enzymes for hydrolysis of cellulose and lignocellu-lose to fermentable sugars (able to complete the biomass hydrolysis during fermentation). 

Further research is also needed in this area. Particularly, (a) to create a new generation of cheap enzymes for hydrolysis of cellulose and lignocellulose to fermentable sugars (able to complete the biomass hydrolysis during fermentation) (b) to develop improved biocatalysts that allow us to simplify the process and reduce energy input and (c) to improve separation and recovery. 

Hydrolysis during melt processing can be suppressed significantly by the addition of such anti-hydrolysis additives. This enables the IV to be maintained across... 

The polymer complex is stable toward inactivation, e.g., alkaline hydrolysis during the polymerization. 

Trimethylsilylation of enolizable carbonyl compounds and alcohols has also been accomplished by the fluoride ion promoted reaction with hexamethyldisilane and ethyl trimethylsilylacetate [48, 49], with high stereospecificity giving Z-enol ethers from ketones [50]. l-Trimethylsilyl-(l-trimethylsilyloxy)alkanes, produced from the reaction of aldehydes with hexamethyldisilane, undergo acid-catalysed hydrolysis during work up to yield the trimethylsilylcarbinols [51]. In the case of aryl aldehydes, the initially formed trimethylsiloxy carbanion produces the pinacol (Scheme 3.1). 

Mildly basic liquiddiquid conditions with a stoichiometric amount of catalyst prevent hydrolysis during alkylation [101] and, more recently, it has been established that solid-liquid or microwave promoted reactions of dry materials are more effective for monoalkylation [102-106] of the esters and also permits dialkylation without hydrolysis. Soliddiquid phase-transfer catalytic conditions using potassium f-butoxide have been used successfully for the C-alkylation of diethyl acetamido-malonate and provides a convenient route to a-amino acids [105, 107] use of potassium hydroxide results in the trans-esterification of the malonate, resulting from hydrolysis followed by O-alkylation. The rate of C-alkylation of malonic esters under soliddiquid phase-transfer catalytic conditions may be enhanced by the addition of 18-crown-6 to the system. The overall rate is greater than the sum of the individual rates observed for the ammonium salt or the crown ether [108]. 

In a similar study, Park has shown125 that cyclic dienes other than cyclo-pentadiene will also undergo a [4 + 2] cycloaddition reaction with the (trimethylsilyl)alkynylcarbene complex (184.b). When 184.b was reacted with 1,3-cyclohexadiene in THF, the diene complex 191 was isolated along with the vinylketene complex 192, which was prone to hydrolysis during column chromatography as expected.123 When 192 was stirred with silica gel and water in hexane, an almost quantitative conversion to the aldehyde complex 193 was observed. 

Fig. 5.7. The acid-catalyzed hydrolysis of penicillins involves first the formation of an acylium ion (5.22), which, by reacting with H20, yields penicil-loic acids 5.24 (Pathway b). The participation of a neighboring 6-acylamido group increases the rate of hydrolysis. During this intramolecular reaction (Pathway a), oxazolylthiazolidines (5.23) are formed and then give rise to the degradation products penicilloic acids 5.24, penicillenic acids 5.25,...

Phospholipid concentration was determined using our modification of Bartlett s procedure (49,53). Cholesterol concentration and purity were determined by HPLC or enzymatically by cholesterol oxidase (49,53). Purity of phospholipids as raw materials, and the extent of their hydrolysis during various steps of liposome preparation and liposome storage, were assessed by TLC and enzymatic determination of the increase in level of nonesterified fatty acids (10,38,49-51,53). 

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