Addition of reagents

Addition (Section 6 1) Reaction in which a reagent X—Y adds to a multiple bond so that X becomes attached to one of the carbons of the multiple bond and Y to the other 1 2 Addition (Section 10 10) Addition of reagents of the type X—Y to conjugated dienes in which X and Y add to adja cent doubly bonded carbons... 

Addition (Section 10 10) Addition of reagents of the type X—Y to conjugated dienes in which X and Y add to the ter mini of the diene system... 

The pH meter usually is coupled to a data recording device and often to a pneumatic or electric controller. The controller governs the addition of reagent so that the pH of the process stream is maintained at the desired level. 

Ai lepiesents an aiyl group. Diaiyl products are obtained after long reaction times. Other Friedel-Crafts catalysts, eg, ZnCl2, FeCl2, FIF, and BF, can also be used. In most cases, stoichiometric amounts of the catalyst ate requited. Flowever, strong complexation of the phosphine by the catalyst necessitates separation by vacuum distillation, hydrolysis, or addition of reagents such as POCl to form more stable aluminum chloride complexes. Whereas yields up to 70—80% are possible for some aryl derivatives, yields of aliphatic derivatives are generally much less (19). 

Titration An analytical method involving the quantitative addition of reagents to a solution until an endpoint is reached as indicated by a color change or a precipitate. 

Another example is tamoxifen (89). Its synthesis begins with Grignard addition of reagent to aryl ketone giving carbinol Dehydration leads to the readily separable and... 

Click Coached Problems for a self-study module on buffer solutions addition of reagents. 

The flasks must be stoppered at all times after the addition of reagents to prevent the loss of bromine. 

Figure 6.1 Proposed structure for the titanium tartrate complex (1) and its transformation after addition of reagents (e. g., TBHP and olefin), forming (+)-2.

The alkynyl reagent 9 was recently introduced for the dia stereoselective synthesis of tertiary propargylic alcohols144. 9 can be prepared as a solid 1 1 complex with tetrahydrofuran by treatment of 9-methoxy-9-borabicyclo[3.3.1]nonane with (trimethylsilylethynyl)lithium, followed by addition of boron trifluoride-diethyl ether complex. The nucleophilic addition of reagent 9 to (R)-2-methoxy-2-methylhexanal (10) afforded a mixture of the diastereomers 11 with a considerable preference to the nonchelation-controlled (3S,4R)-isomer144. 

After the addition of the non-radioactive material, the labeled material is added to the mixture and the mixture allowed to proceed toward equilibriim. In equilibrium analysis the order of addition of reagents is not critical as long as sufficient time is allowed for establishing equilibrium of the complete mixture (3,4). 

Experimental protocol is built into the construction of tree diagrams so that intermediates that are isolated are distinguishable from those that are made in situ, and the order of input dots matches the order of addition of reagents used in the synthesis plan. 

Ionic precipitation involving addition of reagent contributing to the anionic species, OH-ions, in the aqueous medium and interaction with the cationic species, the metal ions, to result in the formation of a compound which, on account of its poor solubility in the medium, precipitates rapidly and is generically alternatively embodied in the description on hydrolysis. 

The corresponding liquid-phase chemistry can be used to promote ion formation by appropriate choice of solvent and pH, salt addition to form M.Na+ or M.NH4+, and postcolumn addition of reagents. The primary applications of ESI-MS are in the biopolymer field. The phenomenon of routine multiple charging is exclusive to electrospray, which makes it a very valuable technique in the fine chemical and biochemical field, because mass spectrometers can analyse high-molecular-mass samples without any need to extend their mass range, and without any loss of sensitivity. However, with ESI, molecules are not always produced with a distribution of charge states [137], Nevertheless, this phenomenon somehow complicates the determination of the true mass of the unknown. With conventional low-resolution mass spectrometers, the true mass of the macromolecule is determined by an indirect and iterative computational method. 

An attempt to chlorinate xylene with the dichlorohy dantoin caused a violent explosion [1], The haloimide undergoes immediate self accelerating decomposition in presence of solvents. Safe conditions (including lower temperatures and progressive addition of reagent to match its consumption) can be developed for its use [2],... 

Dissolved oxygen Winkler reagents Addition of reagent immediately after sampling. Fixed sample should be kept in the dark and analysed as soon as possible. Where measurements are needed on liquids containing high levels of easily oxidisable organic matter, a portable meter should be used, otherwise the copper sul-fate/sulfamic acid mix should be used. DoE recommendation. 

Recently the continuous-addition-of-reagent (CAR) technique [182] was applied for the determination of fluorophores by POCL chemistry [95-99], The applicability of this technique was demonstrated by the determination of natively fluorescent acepromazine in horse plasma [95], the alkaloid harmaline in plasma [96], and other dansylated alkaloids [97], A separation step has also been included and applied to postcolumn detection of PAHs [98] and dansylated P-carboline alkaloids [99],... 

This chapter focuses on analytical CL methodologies, with emphasis on the kinetic connotations of typical approaches such as the stopped-flow, the continuous-addition-of-reagent (a new kinetic methodology) and the pulse perturbation technique developed for oscillating reactions, among others. Recent contributions to kinetic simultaneous determinations of organic substances using CL detection (kinetometric approaches included) are also preferentially considered here. 

Aminophthalate anion Atmospheric pressure active nitrogen Analyte pulse perturbation-chemiluminescence spectroscopy Arthromyces rasomus peroxidase Ascorbic acid Adenosine triphosphate Avalanche photodiode 5-Bromo-4-chloro-3-indolyl 2,6-Di-t< r/-bu(yl-4-mclhyl phenol Bioluminescence Polyoxyethylene (23) dodecanol Bovine serum albumin Critical micelle concentration Calf alkaline phosphatase Continuous-addition-of-reagent Continuous-addition-of-reagent chemiluminescence spectroscopy Catecholamines Catechol... 

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