Meyers procedure

The molecular weight of a moderately volatile substance can be determined by the historically important Victor Meyer procedure, by which the volume of gas produced by vaporization of a weighed sample of an unknown is measured at a given... 

Aldehyde synthesis by triazoline acid hydrolysis has advantages over the Meyers procedure (72JA3243 73JOC36 75JOC2021), in view of the... 

Meyers Procedure. Halogenates and eliminates in-situ Powdered KOH... 

The procedure described is a modification of that given by Kenyon, Meyer, and Hauser.3 No other methods appear to have been used to prepare ethyl 2,4-diphenylbutanoate. A... 

On the basis of these redox potentials it seems likely that direct electron release to the benzenediazonium ion takes place only with iodide. This corresponds well with experience in organic synthesis iodo-de-diazoniations are possible without catalysts, light, or other special procedures (Sec. 10.6). For bromo- and chloro-de-di-azoniations, catalysis by cuprous salts (Sandmeyer reaction, Sec. 10.5) is necessary. For fluorination the Balz-Schiemann reaction of arenediazonium tetrafluoroborates in the solid state (thermolysis) or in special solvents must be chosen (see Sec. 10.4). With astatide (211At-), the heaviest of the halide ions, Meyer et al. (1979) found higher yields for astato-de-diazoniation than for iodo-de-diazoniation, a result consistent with the position of At in the Periodic System. It has to be emphasized, however, that in investigations based on measuring yields of final products (Ar-Hal), the possibility that part of the yield may be due to heterolytic dediazoniation is very difficult to quantify. 

As an example of purification via the ELP fusion approach Meyer and Chilkoti (Fig. 9, left), purified the proteins thioredoxin and tendamistat. For this purpose these target proteins and ELP were genetically fused via a short peptide sequence that included a thrombin cleavage site, which allows the removal of the ELP tag after the purification is completed. The general outline of the purification procedure... 

For PMMA/additive dissolutions, it was not possible to identify any additive characteristic mass peaks, either by direct laser desorption or with matrix-assistance (dithranol, DHBA or sinapinic acid, 4-hydroxy-3,5-dimethoxy-cinnamic acid). This has again been ascribed to very strong interaction between PMMA and additives, which suppresses desorption of additive molecules. Also, partial depolymerisation of pho-tolytically labile PMMA by laser irradiation may play a role, which leads to saturation of the detector by PMMA fragment-ions and disappearance of additive mass peaks below noise level. Meyer-Dulheuer [55] has also reported MALDI-TOFMS analysis of a coating/2-ethylhexyldiphenylphosphate sample. Quantitative determination of the additives by means of MALDI-ToFMS proved impossible. Possibly the development of reproducible (automated) sample handling procedures or thin films might overcome this problem. 

Because both enantiomers, (+) and (-)-camphoric add, are available by oxidation either from natural (+)-D-camphor or from natural (-)-L-borneol, both enantiomers of camphanoyl chloride can be prepared conveniently.3 5 The corresponding enantiomers of camphanic acid were described for the first time by Wreden6and Aschan.7 The three-step procedure, described above is an adaptation of procedures described by Aschan,8 Zelinsky et al.,9 Meyer et al.,10 and Gerlach.3... 

T.J. Meyer The procedure used involved evaporation of the preformed metaliopolymer from a solution in a polar organic solvent like methanol. 

In most cases, extraction is carried out using simple equipment such as Erlen-meyer flasks or test tubes. A sample, plus the appropriate extractant, is added to the container and shaken for a specified amount of time (see the Procedures in the next sections). A flat top or wrist shaker (see Figure 11.1) is commonly used for Erlenmeyer flasks. In some instances, an end-over-end shaker is required. 

Within the two metastable ranges one of the binary components can have an apparent thermodynamic activity larger than 1. The maximum will be reached at x = xgp. In this study x p was derived as a function of W/2.303 RT by iterative procedures using the relevant equations given by Meyering (6 1 ). Subsequently, the thermodynamic activities of the two components were calculated at the extremes which can be reached for variable xsp (Figure 9). Apparently, such high values as log a= 2 are reached only for x > 0.93. 

The chemistry of the isocyanides began when, in 1859 Lieke formed allyl isocyanide from allyl iodide and silver cyanide, and when, in 1866 Meyer ° produced in the same way 1-isocyano-l-desoxy-glucose. In 1867, Gautier used this procedure to prepare alkylisocyanides, and Hofmann introduced the formation of isocyanides from primary amines, chloroform, and potassium hydro-xyde. Gautier also tried to prepare an isocyanide by dehydrating an amine formiate via its formylamine using phosphorus pentoxide, but this process produced no isocyanide. Gautier had not yet realized that acidic media destroyed the isocyanides. 

Meyer and Rossler 101) showed that the overall yields for wet and dry extractive procedures are comparable, being approximately 60% for Some workers have found that yields vary somewhat, due to adsorption of evaporated At onto vessel walls, and to the possibility of the retention of astatine within the target due to the formation of nonvolatile compounds 11). However, the dry evaporation method is more applicable to studies with high-activity targets it is rapid and lends itself to further development within the scope of remote handling techniques. Aspects of both extraction approaches have been discussed widely 2, 7, 33, 89,101,116,120,160). 

Elemental analysis. Elemental analysis was performed with atomic absorption spectroscopy (AAS). Solid samples were first solubilized according to the procedure described by March and Meyers (13). 

Zhang S, Meyer B, Moh GH, Scholz F (1995) Development of analytical procedures based on abrasive stripping coulometry and voltammetry for solid state phase microanalysis of natural and synthetic tin-, arsenic-, and antimony-bearing sulfosalts and sulfides of thalhum, tin, lead, and silver. Electroanalysis 7 319-328. 

Meyer, S. L., Data Analysis for Scientists and Engineers, Wiley, New York, 1975. (This is a more detailed manual on statistics and contains very useful collections of tables, distribution functions, data analysis procedures, and graphical techniques.)... 

The procedure described is essentially that of Victor Meyer. I /(-Dithiane has also been obtained from the py roly sis of the... 

Vacuum Stability Test. See in Vol 1, Introduction , TV XXVI, and under Stability and Instability of Explosives in Vol 6, E438-R Addnl Refs 1) AJ. Clear, Standard Laboratory Procedures for Determining Sensitivity, Brisance and Stability of Explosives , PATR 3278 (Rev 1) (1970), 18-28 2) R. Meyer,... 

The method described in the procedure is a modification of the one originally described by Meyer.1 Irvine 2 showed that this general method could be adapted to works-scale production. 

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