Simplified procedure

A simplified procedure is possible by using polyphosphoric acid as the condensing agent. Add 160 g. of polyphosphoric acid to a solution of 11 g. of resorcinol in 13 g. of ethyl acetoacetate. Stir the mixture and heat at 75-80° for 20 minutes, and then pour into ice-water. Collect the pale yellow solid by suction filtration, wash with a little cold water, and dry at 60°. The yield of crude 4-methyl-7-hydroxycoumarin, m.p. 178-181°, is 17 g. Recrystalbsation from dilute ethanol yields the pure, colourless compound, m.p. 185°. 

Acidic Cation-Exchange Resins. Brmnsted acid catalytic activity is responsible for the successful use of acidic cation-exchange resins, which are also soHd acids. Cation-exchange catalysts are used in esterification, acetal synthesis, ester alcoholysis, acetal alcoholysis, alcohol dehydration, ester hydrolysis, and sucrose inversion. The soHd acid type permits simplified procedures when high boiling and viscous compounds are involved because the catalyst can be separated from the products by simple filtration. Unsaturated acids and alcohols that can polymerise in the presence of proton acids can thus be esterified directiy and without polymerisation. 

For crystal sulfamic acid assay, a simplified procedure of neutralization titration with sodium hydroxide solution may be used. At the end point, Bromothymol Blue (BTB) indicator changes color from yellow to yellowish green. A 1-mL solution of l/2NNaOH is equivalent to 0.0485 g of sulfamic acid. 

On occasion the changes in gas flow and in the mole fraction of inert gas are so small that the inclusion of terms such as (1 — y) a.ndy%M can be neglected or at least can be included in an approximate way. This leads to some of the simplified procedures described later. 

It is a common procedure to assume certain conditions for the chromatographic system and operating conditions and, as a result, simplify equations (20) and (21). However, in many cases the assumptions can easily be over-optimistic, to say the least. It is necessary, therefore, to carefully consider the conditions that may allow such simplifying procedures and take steps to ensure that such conditions are carefully met when such expressions are used in practice. Now, the relative magnitudes of the resistance to mass transfer terms will vary with the type of columns (packed or capillary), the type of chromatography (GC or LC) and the type of particle, i.e., porous or microporous (diatomaceous support or silica gel). 

This simplified procedure gives the sulfonic acid in very good yield, however the same procedure is not applicable to the synthesis of triflic acid, which would require the synthesis of trifluoromethyllifhium. This procedure also is not applicable to the preparation of the sulfonic acids requiring the use of perfluoropropyl or isopropyllithium intermediates... 

Hengstebeck [137] presents a simplified procedure for reducing a multicomponent system to an equivalent binary using the key components. From this the number of stages or theoretical plates and reflux can be determined using conventional binary procedures and involving the McCabe-Thiele method. 

Verink, E. D., Simplified Procedure for Constructing Pourbaix Diagrams , Corros. Sci., 23, 371 (1967)... 

The attractions of trivalent baths are their lower toxicity, greater efficiency, and a considerably simplified procedure for efficient treatment. 

With this simplified procedure it is much easier to protect the system from atmospheric moisture, which must obviously be excluded. Modem K-F Titrators are equipped with special titration vessels which are designed to prevent the ingress of atmospheric moisture. Many also have microprocessors attached which will carry out the requisite operations automatically and will often provide a print-out of the results including the percentage moisture content. 

In Venezuela, there is no official fast-track system. However, brief-mode registration is available for generic products for which a bioavailabilily study has been undertaken. Similarly, Malaysia has an abridged procedure for registration of products classified as non-scheduled poisons. This type of simplified procedure does not, in essence, differ from the use of less stringent registration requirements for certain categories of products as seen, for example, for herbal medicines in Australia and the Netherlands. 

The problem with the above simplified procedure is that it may yield parameters that result in erroneous phase separation at conditions other than the given experimental ones. This problem arises when the given data are sparse or not well distributed. Therefore, we need a procedure that extends the region over which the stability constraint is satisfied. 

Bhatia, N., McDonald, K. A., Jackman, A. P., and Dandekar, A. M, A simplified procedure for the purification of trichosanthin (a type 1 ribosome inactivating protein) from Trichosanthes kirilowii root tubers, Prot. Purif. Expression, 7, 143, 1996. 

The simplified procedure with a direct solution can also be used. The excess head loss resulting from the pipe length is given by Equation 4-30. The friction factor/has already been determined ... 

Hirschfeldt (H8) has suggested that the small differences in migration rate of the different HpHb complexes in agar gel at pH 8.6 with a Ca++-containing barbiturate buffer can be used for ascertaining the Hp type. In our opinion the results obtained by this simplified procedure are less reliable than those obtained by the somewhat more complicated starch gel electrophoretic method. 

In this work, we initially performed a thorough study of the challenges to synthesize DBX-1 when using these raw NaNT solutions, including an investigation of the specific impurities, which ultimately prevent formation of DBX-1. A safer and simplified procedure for the preparation of NaNT was thus developed and detailed herein. It is demonstrated that the produced material from the new procedure is of sufficient purity to be used for the preparation of DBX-1. The DBX-1 prepared from this NaNT functions comparably to current state-of-the-art DBX-1 in stab detonators and is of comparable sensitivity. 

RA Houghten, MK Bray, ST Degraw, CJ Kirby. Simplified procedure for carrying out simultaneous multiple hydrogen fluoride cleavages of protected peptide resins. Ini J Pept Prot Res 27, 673, 1986. 

Rowell, R.M., Simonson, R. and Tilhnan, A.-M. (1986a). A simplified procedure for the acetylation of chips for dimensionally stabilized particleboard products. Paperi ia Puu, 68(10), 740-744. 

Discontinuous approaches are used through necessity in radiometric assays (Oldham, 1993) and in liquid- and gas-chromatography-based protocols (Syed, 1993). Many commercially available kits designed to measure a particular enzyme activity combine absorbance and fluorescence platereader-based technologies with assay protocols that could be done continuously. However, since many users of these kits have little experience in enzymology, assay instructions usually outline a simplified procedure whereby a... 

However, this simplified procedure should be used only where no marketing authorisation can be obtained through procedures for t)q)ical medicinal products. In order to promote harmonisation, Member States are expected to recognise registrations of traditional herbal medicinal products granted by another Member State based... 

A simplified procedure for detecting the M. aeruginosa toxins was devised. A 20.0 mg sample of lyophilized cells was extracted for 1 hr with 1 ml of 38% ethanol, 5% n-butanol, 50 mM ammonium acetate pH 6.0, shaking the suspension manually for a few seconds several times. The suspension was then centrifuged (5 min at 12,000 Xg). 

A simplified procedure for design is to assume that both tj and — AH/Cp are constant. If, then, eqn. (60) (the heat conservation equation) is divided by eqn. (59) (the mass conservation equation) and integrated, one immediately obtains... 

The coupling reaction proceeds better when a rigorously degassed Raney nickel catalyst is used, but a nickel catalyst prepared by a much simplified procedure (Note 9) is also effective. The coupling may also be promoted by other elements, including copper and palladium. 

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