Experimental procedure preparation

N.B. The reaction involves oxidation with a source of nitrosonium ion (NO ) in the presence of an alcohol and a source of H to give a phenylglyoxal acetal. Experimental procedure Preparation by reaction of methyl nitrite with p-hydroxyacetophenone in 1.25 N methanolic hydrogen chloride between 0° and 5° for 4 h (72%). The methyl nitrite source was supplied by adding gradually 33% aqueous sulfuric acid to a sodium nitrite solution in aqueous methanol (1 1) under nitrogen. 

Experimental procedure. Prepare a solution of 40% ethanol-water v/v by mixing 40 cm of ethanol with 60 cm of water. Fill an Erlenmeyer flask with 75 cm of this solvent, place... 

Experimental procedure. Prepare the following in water 100 cm each of solutions 0.01 M iodine and 1 M in sulfuric acid, 500 cm of an aqueous sodium acetate solution (IM), and 1000 cm of a standardised solution of sodium thiosulfate (0.01 M). As iodine is sparingly soluble in water, the solution of 0.01 MI2 is prepared by dissolving the appropriate mass of iodine in an aqueous solution of 0.01 M KI. Also prepare a solution of starch indicator in water as follows mix 1 g of starch and 1 cm of hot water to form a paste, add 1 cm of the 1.0 M H2SO4 solution and 0.1 g NaHSOj and finally dilute to 250 cm. To a 250 cm Erlenmeyer flask, add the following quantities of the above solutions ... 

Experimental procedure. Prepare potassium ferrioxalate by adding, with stirring, a solution of potassium oxalate (1.5 M) to iron(lll) chloride (1.5 M) in the volume ratio 3 1. Recrystallise the precipitate obtained from water, and dry the potassium ferrioxalate crystals obtained and store in the dark. Prepare a 0.006 M solution of this actinometer in a 1 dm flask by dissolving 2.847 g of the crystals obtained in 800 cm water and adding sufficient... 

Experimental procedure. Prepare four solutions of potassium hexacyanoferrate(lll) (1.0X10 M ) in water containing sodium nitrate of different concentrations (e.g. 0.02, 0.05, 0.1 and 0.2 M). Prepare a 0.010 M solution of nitric acid, 0.001% of the disodium salt of EDTA and 2.5 X10 " M ascorbic acid. In the preparation of this solution, ascorbic acid must be the last solution to be added. Pipette 25 cm of one of the solutions of K3[Fe(CN)g]/NaN03 into an Erlenmeyer flask and add 25 cm of the solution of ascorbic acid/nitric acid. Start the stopwatch and shake for a few seconds. Transfer the solution to the cuvette and measure the absorbance at 418 nm every minute for 20 min. To obtain the absorbance corresponding to f = 0, add 25 cm of water and 25 cm of the solution of K3[Fe(CN)g]/NaN03 and record the absorbance. Repeat the process for all the solutions over the whole range of NaNOj concentrations. 

Experimental procedure Preparation of aryl zinc halides... 

Experimental procedure Preparation of unsubstituted poly(p-phenylenevinylene)... 

The experimental procedure to be followed depends upon the products of hydrolysis. If the alcohol and aldehyde are both soluble in water, the reaction product is divided into two parts. One portion is used for the characterisation of the aldehyde by the preparation of a suitable derivative e.g., the 2 4-dinitrophenylhydrazone, semicarbazone or di-medone compound—see Sections 111,70 and 111,74). The other portion is employed for the preparation of a 3 5-dinitrobenzoate, etc. (see Section 111,27) it is advisable first to concentrate the alcohol by dis tillation or to attempt to salt out the alcohol by the addition of solid potassium carbonate. If one of the hydrolysis products is insoluble in the reaction mixture, it is separated and characterised. If both the aldehyde and the alcohol are insoluble, they are removed from the aqueous layer separation is generally most simply effected with sodium bisulphite solution (compare Section Ill,74),but fractional distillation may sometimes be employed. 

Most of these compounds, for instance pyrazole itself, are today commercially available, so there is only a minor interest in detailing the experimental procedures used. The best way to prepare pyrazole is the Protopopova method (Section 4.04.3.3.2) and a modification using hydrazine hydrate instead of a hydrazine salt has recently been patented (80GEP2922591). 

Additional suggested resources for the reader include introductory articles on scanning probe techniques for materials properties measurement [82,83J. A comprehensive manual describing various surface preparation techniques, experimental procedures and instrumentation is also a good resource [84J, although the more recent modulation based techniques are not covered. Key textbooks include Johnson s on contact mechanics [51J and Israelachvili s on surface forces [18J, as well as a treatment of JKR/DMT issues by Maugis [85J. 

Acknowledgment The authors wish to express their gratitude to Dr. J. Edwards of Syntex Research who provided the experimental procedure utilizing silver carbonate on Celite. We are also indebted to the Synthetic Chemical Research Department of Merck Sharp Dohme Research Laboratories for providing time to complete this review and also to Miss Joanna Mohr for her patience and care in preparing the manuscript. 

The benzilic acid rearrangement of steroid a-diketones is often the preferred method for ring contraction. Yields are generally excellent, and in several instances the reaction has been shown to be stereospecific. Preparation of the starting a-diketones is discussed below and illustrated with several excellent experimental procedures. 

The next seven references are cited not because of the experimental procedures described but because they indicate diversification in the types of enamines prepared and studied. Both Paquette (25) and Kasper 26) have condensed 2,5-methylene-l,2,5,6-tetrahydrobenzaldehyde (5-nor-bornene-2-carboxyaldehyde) (2) with several cyclic and open-chain aliphatic secondary amines. Kasper studied the ratio of endo to exo aldehyde formed upon hydrolysis of these enamines and the dihydro enamines. Paquette investigated the addition of sulfene to the enamines. -Fluoro-... 

Nevertheless the Elbs reaction is a valuable method for the preparation of dihydroxy benzenes. The experimental procedure is simple, and the reaction conditions are mild a variety of functional groups is tolerated. 

Rearrangements and other side-reactions are rare. The ester pyrolysis is therefore of some synthetic value, and is used instead of the dehydration of the corresponding alcohol. The experimental procedure is simple, and yields are generally high. Numerous alkenes have been prepared by this route for the first time. For the preparation of higher alkenes (> Cio), the pyrolysis of the corresponding alcohol in the presence of acetic anhydride may be the preferable method." The pyrolysis of lactones 9 leads to unsaturated carboxylic acids 10 ... 

The reference in parentheses following the name of the compound is to an experimental procedure for the preparation of that compound. 

Oxabicyclo[4.1.0]hept-3-enes with a bromo substituent in position 2 can be converted to oxepins 11 by reaction with an appropriate base such as potassium ter+butoxide or triethylamine (see the experimental procedures for the preparation of the parent system in Houben-Weyl, Vol. 6/ld, pi78 and Vol. 6/4, p462).12,156,157 Usually the reaction products are mixtures of oxepin 11 and benzene oxide 12. In the case of ZerZ-butyl 7-oxabicyclo[4,1.0]hept-3-ene-2-carboxylate, the equilibrium lies completely on the benzene oxide side 12a.158... 

Pure di-2-propenylzinc2,8,9 10, bis(2-methyl-2-propenyl)zinc11 or di-2-butenylzinc11 are best prepared by the metal exchange between dimethylzinc and the appropriate triallylborane, which is produced in situ from the Grignard reagent and boron trifluoride-diethyl ether complex. The purification is accomplished by distillation, for experimental procedure, see ref 2, p619. 

The reaction proceeds with high regioselectivity for oxidation at the less substituted a-carbon. Methanol is commonly used as the solvent, although higher alcohols are also used for some detailed experimental procedures refer to the literature60,61. Some examples of compounds prepared via electrochemical alkoxylation are ... 

FIGURE 8 Release of cortisone acetate from 10% loaded microspheres of various polyanhydrides. The microspheres were prepared by an interfacial condensation. Details of the experimental procedure are described in the text. 

The experimental procedure for the preparation of analytically pure hydrocarbon salts was as follows. First, the deep green solution of Kuhn s... 

Different performanee eriteria are laid down for injeetable and ophthahrtic preparations, topical preparations and oral hquid preparations. Inhibition of the challenge organism is determined by viable coimting teehniques. The British Pharmacopoeia (1993) should be eonsulted for full details of the experimental procedures to be used. 

In this section, a description of the experimental procedure used to prepare and characterize metal nanoclusters stabilized by DMAA-based microgels (M5, MIO, M20) is provided. Details of the experimental procedure used to prepare nanoparticles stabilized by MMA-based microgels have been reported elsewhere [13b]. 

Polymer preparation. PV0CC1 sample has been prepared by free-radical polymerization of pure V0CC1 (acquired from the SNPE, purity 99 ) in CH2CI2 at 35°C using dicyclohexyl peroxydicarbonate as initiator. The experimental procedure has been described previously ( 18, 1 9). The molecular weight Mn of this sample is equal to 50,000. 

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