As Secondary Products

The photolysis of chlorodiazirine was investigated in several cases. From chloromethyl-diazirine (232) vinyl chloride was formed as the stable primary product of stabilization of chloromethylcarbene, with acetylene and hydrogen chloride as secondary products. Some 1,1-dichloroethane was assumed to have been formed through a linear diazo compound by reaction with HCl. Added HBr yielded 1-bromo-l-chloroethane (76MI5Q800). 

Hydrolysis of the polymers yields H2SO4 and H2SO5 (p. 712), with H2O2 and O2 as secondary products. 

The stable dicyanomethylides 274, made directly from the triazolopyridines and tetracyanoethylene oxide (TCNEO) reacts more slowly with MEP in acetonitrile to give mainly indolizines, with cyclazines as secondary products formed... 

At the moment, only three in vitro studies have been performed on Bfx metabolic behavior, hi one case, it has been shown that Bfxs are able to be reduced by oxyhemoglobin to the corresponding o-nitroaniline derivatives (Scheme 5) [237]. hi the reaction between compoimd 135 and oxyhemoglobin compound 136 was generated as secondary product resulting from both nitrile hydrolysis and deoxygenation. This study indicates that blood is a possible site for metabolism of Bfxs with the consequent methemoglobinemia. 

In the case of the oximes of the aldose sugars, the situation is more complicated because of the possibility of both open-chain and cyclic structures. That aldose oximes can react in the open-chain form follows from the formation of the nitriles and from the isolation of acylated open-chain aldose oximes as secondary products in preparation of nitriles. For example, Wolfrom and Thompson, by the action of sodium acetate-acetic anhydride on n-glucose oxime, not only obtained pentaacetyl-D-glucononitrile, in 40% yield, but also isolated a small amount of hexaacetyl-oWeAydo-D-glucose oxime (V) identical with that prepared by mild acetylation of pentaacetyl-aWe%do-D-glucose oxime (IV) whose structure was assured by its formation from pentaacetyl-aldehydo-D-glucoae (III). 

Other indices measure a secondary stage of oxidation, such as the anisidine value (ANV), pointing to formation of carbonyl compounds, capable of undergoing condensation reactions with p-anisidine, and the thiobarbituric acid reactive substance (TBARS) pointing to the presence of malondialdehyde (MDA) in particular. In biological systems, TBARS is of widespread use as a measure for the extent of oxidation damage. Another test for stability of oils to oxidation is based on the development of acidity as secondary product, for example, standards using the Rancimat equipment or a similar setup. 

Carbonylation of the urea 27 in the presence of Pd(0) and KOAc as base is a useful route to 4-butyl-2-phenyl-23,44-tetrahydro-l/f-2,4-benzodiazepine-13-dione (28) <99TL2623>. Also isolated from this reaction as secondary product is IV-n-butylisoindoline. Pyrolysis of the cyclobutenones 29 afford the diazepines 30 in moderate yield <99JOC707>. 

The mechanism of phenylacetate transformation can be described as shown in scheme 3. Phenylacetate adsorbs on a protonic center and then can either rearrange into ortho-hydroxyacetophenone (Fries rearrangement) or desorb phenol. The adsorbed acylium ion can then react with phenol (if the conversion is high enough) to give ortho- and para-hydroxyacetophenone which will then appear as secondary products. It can also react with phenylacetate to give ortho- and para-acetoxyacetophenones or react with ketene to give the condensation products. 

Triazolines with an electron-withdrawing substituent in the 5-position are rare they are obtained as secondary products in the nonregioselective addition of azides to methacrylic derivatives (Scheme 75). Their thermolysis is similar to that of the 4-isomers a mixture of aziridine and enamine is formed.67... 

Hydroisomerization proceeds towards thermodynamic equilibrium which is approximately reached between the normal, mono-branched and di-branched structures at high degrees of overall conversion. Hydrocracking, however, is severe under these conditions. It is evident from Table II that monomethyl isomers are primary products the same is apparently true for monoethyl isomers although due to thermodynamic reasons lower concentrations are obtained. Dimethyl isomers including those containing a quarternary carbon atom are formed as secondary products. However, trimethyl isomers are formed very slowly so that their concentrations do not reach equilibrium values. It follows from this that the number of ramifications is deciding as to whether a branched isomer is a primary, secondary or tertiary product in hydroisomerization of n-octane and n-nonane. 

It should, however, be pointed out that - where applicable - product composition can be significantly different. For example, whereas thiazolium catalysts afford exclusively dihydroxyacetone with formaldehyde as substrate, the triazolium systems afford glycolic aldehyde (plus glyceraldehyde and C4 and C5 sugars as secondary products) [246], Catalyst-dependent differences in the relative rates of the partial reactions within the catalytic cycle (Scheme 6.105) most probably account for this phenomenon. A subsequent study by Enders et al. on chiral triazolium salts identified the derivative 233 as a first catalyst for the asymmetric benzoin condensation that affords substantial enantiomeric excesses (up to 86%) with satisfactory chemical yields (Table 6.3) [247]. 

From their results, the authors have proposed a consecutive reaction scheme with glucofuranosides as primary products and glucopyranosides as secondary products. 

In the autoxidation of neat hydrocarbons, catalyst deactivation is often due to the formation of insoluble salts of the catalyst with certain carboxylic acids that are formed as secondary products. For example, in the cobalt stearate-catalyzed oxidation of cyclohexane, an insoluble precipitate of cobalt adipate is formed. 18fl c Separation of the rates of oxidation into macroscopic stages is not usually observed in acetic acid, which is a better solvent for metal complexes. Furthermore, carboxylate ligands may be destroyed by oxidative decarboxylation or by reaction with alkyl hydroperoxides. The result is often a precipitation of the catalyst as insoluble hydroxides or oxides. The latter are neutralized by acetic acid and the reactions remain homogeneous. 

LPG is a blend of propane and butane obtained as secondary products of natural-gas exploration or during crude oil processing. For this reason LPG is included usually in alternative fuels. Although the combustion properties of LPG are excellent, its wider usage is prevented by supply limitations and safety problems. 

Some bacterial and fungal strains are capable of differentiation (sporulation, filamenta-tion). This property can affect product formation and the physical properties of the fermentation broth. Some enzymes are synthesized as secondary products and their production does not appear to be growth associated. Production strains are distinguished on the basis of their fermentation behavior such as viscosity or recoverability. They can also be distinguished by patent or proprietary... 

The overall reaction is energy yielding, and allows sufficient ATP production to support reverse electron transport for CO2 fixation. However, the first step, oxidation of NH3 to hydroxylamine, requires the input of reducing power. The second step, hydroxylamine oxidation, yields four electrons. These join the electron transport chain at the level of ubiquinone, from which two are shunted back to AMO for activation of NH3. The N oxidation and electron transport pathways in Nitrosomonas are linked in the cytoplasmic membrane and periplasmic space detailed information from the N. europaea genome (Chain et al., 2003) is consistent with the previous biochemical characterizations of the system (Whittaker et al., 2000). Depending on conditions (and enhanced at low oxygen concentrations), nitric oxide (NO), nitrous oxide (N2O) and even dinitrogen gas (N2) have been reported as secondary products... 

Mn(C0)5N02] and [Mn(C0)50N0] were obtained as secondary products in the reaction of Mn2(CO),o and N2O4 in petroleum ether (10)... 

Wastes from lead-rich mineral deposits typically form anglesite in sulfate-dominant environments, but in limestone-dominated host rocks and in gangue containing abundant carbonates, both cerussite [PbCOs] and hydrocerussite [Pb3(-003)2(01-1)2] have been reported as secondary minerals in mining-related wastes. Several carbonate and hydroxycarbonate minerals of copper and zinc were reported by Hudson-Edwards et al. (1996) as secondary products in stream sediments in the Tyne Basin, England. 

Separation of Liquids.— The methods of separation are of two general types, one for liquids and the other for solids. A liquid product may consist of the entire reaction mixture, or it may be obtained as a distillate. The product may contain acid or alkali or it may be mixed with water, alcohol or other liquids used in the reaction or obtained as secondary products. 

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