Typical Experimental Procedures

The most used method is based on application of the Mayo equation (eq. 5). For low (zero) conversion polymerizations carried out in the presence of added transfer agent T, it follows from eq. 5 that a plot of 1/ Xn vs [T]0/[M]0 should yield a straight line with slope Clr.12 Thus, a typical experimental procedure involves evaluation of the degree of polymerization for low conversion polymerizations earned out in the presence of several concentrations of added transfer agent. The usual way of obtaining Xn values is by GPC analysis of the entire molecular weight distribution. 

On the other hand, the method of Mukaiyama can be succesfully applied to silyl enol ethers of acetic and propionic acid derivatives. For example, perfect stereochemical control is attained in the reaction of silyl enol ether of 5-ethyl propanethioate with several aldehydes including aromatic, aliphatic and a,j5-unsaturated aldehydes, with syir.anti ratios of 100 0 and an ee >98%, provided that a polar solvent, such as propionitrile, and the "slow addition procedure " are used. Thus, a typical experimental procedure is as follows [32e] to a solution of tin(II) triflate (0.08 mmol, 20 mol%) in propionitrile (1 ml) was added (5)-l-methyl-2-[(iV-l-naphthylamino)methyl]pyrrolidine (97b. 0.088 mmol) in propionitrile (1 ml). The mixture was cooled at -78 °C, then a mixture of silyl enol ether of 5-ethyl propanethioate (99, 0.44 mmol) and an aldehyde (0.4 mmol) was slowly added to this solution over a period of 3 h, and the mixture stirred for a further 2 h. After work-up the aldol adduct was isolated as the corresponding trimethylsilyl ether. Most probably the catalytic cycle is that shown in Scheme 9.30. 

Organozinc copper reagents have very broad synthetic potential and a number of typical experimental procedures have recently been published [99, 100]. 

Figure 15.19a shows the typical experimental procedure and apparatus for catalyst preparation by SCCO2 treatment. For example, [Rh(OAc)2]2 and Pt(acac)2 were... 

This method can be used with any metal carbonate and any acid, providing the salt produced is soluble. The typical experimental procedure is similar to that carried out for an acid and a metal. For example, copper(n) carbonate would be added in excess to dilute nitric acid. Effervescence would be observed due to the production of carbon dioxide. 

Organic Reactions. Began publication in 1942, Volume 34 (1986). Each volume contains detailed surveys of a small number of named reactions, with a range of typical experimental procedures. 

Typical Experimental Procedure (Scale Up). Stoichiometric amounts (6.2 mL) of 0.1 M methanolic solutions of the three supporting Ugi components and ethyl glyoxalate (7.75 ml) were combined and stirred at reflux overnight. The solvent was evaporated in vacuo and crude Ugi product dried under high vacuum. A 10% solution of AcCl in MeOH (25 mL) or a 10% solution of TFA (trifluoroacetic acid) in dichloroethane (25 mL) was added to the crude material and stirred at room temperature overnight. The solvent was evaporated in vacuo. The crude material was preadsorbed onto flash silica and purified by flash column chromatography (EtOAc hexane, 1 4) to yield the desired product 57 (192 mg, 71%) as a white solid. 

Typical Experimental Procedure (Plate Production). Equal amounts (0.1 mL) of 0.1 M solutions in methanol of the four components are employed generating a theoretical 10 qmol of final product. Reagents were dispensed into a 96-well plate using either a Quadra 96 or Rapid Plate (Zymark) 96-well dispenser. The deprotection/cyclization steps were... 

Typical Experimental Procedure (Scale Up). The following procedure was followed for the large-scale preparation of 99 Solutions of N-(tert-butoxycarbonyl)-D-prolinal (0.1 M, 10 ml in MeOH), l-(2-pyrimidyl) piperazine (0.1 M, 10 ml in MeOH), methyl isocyanoacetate (0.1 M,... 

Typical Experimental Procedure (Plate Production). Production of an 80-member array was successfully completed using a Charybdis 96-well Teflon block, encapsulated in a Calypso reaction frame assembly. Reagents were transferred into the 96-well plate using either a Quadra 96 or Rapid Plate 96. The blocks were then heated at 65° for 3 days and the solvent evaporated in vacuo at 65°. Scavenging with PS-TsNHNH2 (6 equiv.) and PS-NCO (1 equiv.) was performed at the plate level and the resins were added using a Millipore column loader. Evaporation was performed in a Savant evaporator for 2 h. 

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. 

It should be pointed out that despite their high reactivity carbenes are selective, and while they will react with hydrocarbons in the absence of nucleophiles, a nucleophilic group exposed within the bilayer will preferentially be attacked. Some properties of the three most thoroughly tested reagents iodonaphthyl azide, adamantane diazirine, and 3-trifluoromethyl-3-(m-iodophenyl)diazirine are summarized in Table 6.1. There follows a brief description of a typical experimental procedure, a discussion of control experiments, and several caveats, followed by some examples of the applications of hydrophobic reagents. 

Addition reactions with Mode A are popular, and most addition reactions are classified into this group. The most typical experimental procedure is the treatment of alkyl halides (RBr, RI) and electron-deficient olefins with Bu3SnH in the presence of AIBN. Bu3GeH or Ph3GeH can be also used instead of Bu3SnH however, there are rather expensive and less reactive. Typical addition reactions are shown below, in... 

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