Experimental procedures 3- phenol

The synthetic procedure described is based on that reported earlier for the synthesis on a smaller scale of anthracene, benz[a]anthracene, chrysene, dibenz[a,c]anthracene, and phenanthrene in excellent yields from the corresponding quinones. Although reduction of quinones with HI and phosphorus was described in the older literature, relatively drastic conditions were employed and mixtures of polyhydrogenated derivatives were the principal products. The relatively milder experimental procedure employed herein appears generally applicable to the reduction of both ortho- and para-quinones directly to the fully aromatic polycyclic arenes. The method is apparently inapplicable to quinones having an olefinic bond, such as o-naphthoquinone, since an analogous reaction of the latter provides a product of undetermined structure (unpublished result). As shown previously, phenols and hydro-quinones, implicated as intermediates in the reduction of quinones by HI, can also be smoothly deoxygenated to fully aromatic polycyclic arenes under conditions similar to those described herein. 

Experimental Procedure. Morwell brown coal was solubilised by reacting with phenol, in the presence of para toluene sulfonic acid, at 1830C, and the reaction product was then separated into four fractions and analysed according to procedures described elsewhere (lj. The structural characteristics of the four fractions as determined by the present work and confirmed by reference to the literature ( ,3) are summarised in Table I. As these characteristics are influenced to some extent by the presence of chemically combined phenol, the content of this in each fraction is also estimated. 

The technical production of poly(benzimidazole) (PBI) is also carried out in two steps. In the first step an aromatic tetramine is condensed with the diphenyl ester of an aromatic dicarboxylic acid at 220-260 °C, yielding a poly(amino amid) with elimination of phenol. Ring closure with elimination of water occurs in the second step (solid-phase polycyclocondensation), conducted at 400 °C and yielding the polybenzimidazole (experimental procedure, see Table 2.3). 

The phenolic group is activating and ortho-para directing. The electrophilic substitution reactions in the nucleus in (a) nitrosation and nitration (b) halogenation and (c) acylation and alkylation, are therefore particularly facile, and various experimental procedures need to be adopted to control the extent of substitution (cf. substitution reactions of aromatic amines and their acylated derivatives, Sections 6.6.1 and 6.6.2, pp. 906 and 916 respectively). 

Experimental procedures are given in Expt 6.107 for o- and p-hydroxy-propiophenones (R = Et). The ortho-para ratio in the product is influenced by the nature of the alkyl residue, the temperature, the solvent and the amount of aluminium chloride used generally low temperatures favour the formation of p-hydroxyketones. It is usually possible to separate the two hydroxyketones by fractional distillation under reduced pressure through an efficient fractionating column or by steam distillation the ortho isomers, being chelated, are more steam volatile. It may be mentioned that Clemmensen reduction (cf. Sections 5.1.3, p. 476 and 6.1.1, p. 826) of the hydroxyketones affords an excellent route to alkyl phenols. 

Typical experimental procedures are as follows The test drug candidate is incubated with pooled human liver microsomes (e.g., 1 mg protein/mL) that were previously preincubated with ABT (1 or 2 mM) for 30 minutes at (37 1)°C in the presence of an NADPH-generating system. Incubations of the drug candidate in the absence of ABT serve as controls. For hepatocytes, suspensions of freshly isolated or cryopreserved hepatocytes (lx 106 cells/ mL) are preincubated with 100-pM ABT for 30 minutes in 0.25 mL of Krebs-Henseleit buffer or Waymouth s medium (without phenol red) supplemented with FBS (4.5%), insulin (5.6 pg/mL), glutamine (3.6 mM), sodium pyruvate (4.5 mM), and dexamethasone (0.9 pM) at the final concentrations indicated. After the preincubation, the drug candidate is added to the incubation and the rate of metabolism of the drug candidate is compared in hepatocytes or microsomes with and without ABT treatment. A marked difference in metabolism caused by ABT is evidence that CYP plays a prominent role in the metabolism of the drug candidate. 

The bond performances of lignin-phenolic resin systems were studied through a series of experiments, each designed to elucidate a facet of the problem. The resin preparation and panel fabrication procedures were, however, maintained as uniformly as possible. Thus, unless otherwise specified, the experimental procedures described below were used in the study. 

The initial research objectives included developing a simple experimental procedure to study how the graft polymers, polystyrene, and a commercial phenol formaldehyde resin interact when combined with wood under heat and pressure. Two-ply lap shear test specimens were used for a comparative test. 

The tetrahydropyranylation of alcohols under solvent-free conditions is efficiently catalyzed by bismuth triflate (0.1 mol%). The experimental procedure is simple and works well with a variety of alcohols and phenols. The catalyst is insensitive to air and small amounts of moisture, easy to handle and relatively non-toxic. The deprotection of THE ethers is also catalyzed by bismuth triflate (1.0 mol%). 

Among the non-steroidal alcohols applied to the Oppenauer oxidation are the cis and trans a-decalols (14), which give excellent yields of the corresponding a-decalones (IS).22 Oxidation of phenolic compounds bearing pendent aliphatic secondary alcohols can be readily performed without prior protection of the phenolic alcohol functionality.23 Acid-sensitive acetal 16 is smoothly converted to the corresponding ketone 17, by exploiting a modified experimental procedure.3,24... 

In macroscopic chemistry, the experimental procedures for the bromination of aromatic compounds depend greatly on the nature and reactivity of the starting material. Activated aromatics such as phenol and aniline can be brominated to the tri-and tetrabrominated derivatives by using dilute aqueous solutions of bromine, whereas a controlled monobromination is very challenging and often requires cryogenic conditions. On the other hand, thermally controlled brominations of less activated aromatics such as toluene are rather slu ish reactions. Th often require photoinitiation and the use of Lewis adds as catalysts. 

Although this test is used primarily for detecting phenols, it can also be applied as a qualitative test for alcohols. Discussion about and experimental procedures for this test are given in Section 25.12. 

The monomers were synthesized using a similar experimental procedure. Starting from 4-hydroxybenzaldehyde, the phenolic group was first blocked with the vinyl ethers to form the acetal-benzaldehydes and then Wittig reaction converted the aldehyde group into the vinyl functionality. To demonstrate the reaction sequences. Scheme 1 illustrates the preparation of 4-(l-phenoxyetho) )styrene and its free radical polymerization. 

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