Product indicators

Problem A knockback condenser mounted on a C3 splitter reflux drum exhibited liquid carryover (as evidenced by the vent line icing-up). This indicated product loss from liquid caixying over rather than dripping back into the reflux drum. Also the vent line metallurgy would not withstand the cold temperatures produced. 

The following reactions are unlikely to provide the indicated product in high yield. What is wrong with each ... 

One set of experiments was done with both Q and B present at initial concentrations much higher than that of A. With k, kx, and k-j known from other work, the value of k was then estimated, because under these conditions the steady-state approximation for [I] held. To check theory against experiment, one can also determine the products. In the case at hand, meaningful data could be obtained only when concentrations were used for which no valid approximation applies for the concentration of the intermediate. With kinsim, the final amount of each product was calculated for several concentrations. Figure 5-3 shows a plot of [P]o<4R] for different ratios of [B]o/[Q]o the product ratio changes 38-fold for a 51-fold variation in the initial concentration ratio. Had the same ratios of [B]o/tQ]o been taken, but with different absolute values, the indicated product ratios would not have stayed the same. Thus, this plot is for purposes of display only and should not be taken to imply a functional relationship between the quantities in the two axes. 

Analysis by thin layer chromatography (TLC) indicates product formation and a small amount of starting material. TLC was performed on Merck Silica gel 60 F-254 coated on aluminum sheets. Product 3 has Rf = 0.44 (elution with 70 30 petroleum ether-ethyl acetate visualization with iodine vapor). 

Reactions with molecular species above the arrow e.g. RIO) involve subsequent reactions with these species to produce the indicated products. In most cases the reactants shown to the left of the arrow participate in the slowest or rate-determining step]. The CH3O radical formed in Rll then follows reaction R7. The H02 radical formed in RIO is the other member of the family and is linked with HO in a variety of chain reactions. These radicals are produced following HO attack on hydrocarbons or by photodissociation of oxygenated hydrocarbons such as formaldehyde (RIO) and acetaldehyde ... 

Fig. 9. HCCO and CH2 product lab angular distributions from the 0(3P) + C2H2 reaction at Ec = 9.5kcalmol 1. Solid lines are best-fit curves obtained from the best-fit product angular and translational energy distributions (adapted from Ref. 33). The Newton diagram of the experiment is also shown there the Newton circles delimit the maximum velocity that the indicated products can attain assuming that all the available energy is channelled into translation.

Here "A" indicates products produced by thermostatting the calorimeter and its contents prior to oxidation and "ox" indicates products produced from the thermostatted samples by dry oxidation. The subscripts s and v refer to the phase (solid or vapor) in which the product remains or to which the product is transferred. Thus CA(s) rePresents the amount of carbon actually available as fuel at each temperature, CQX sx represents the amount of carbon remaining as oxygenated bitumen, represents the amount of carbon... 

Figure 6.10 shows the data flow of the software tool BayAPS PP for optimal capacity assignment for given stochastic demands. Transaction data about demand and inventories is typically imported from SAP R/3 as indicated, production capacity master data and side conditions are stored in the software tool. Forecasts can be taken from a forecast tool or from SAP R/3. The output ofthe tool is a list ofpriorities of products and their lot sizes, which are optimal based on the presently available information. Only the next production orders are realized before the computation is repeated, and the subsequently scheduled production is only a prediction. 

Figure 27. Mechanism of radiation induced chain scission in PMMA. Homolysis of the mainchain-carbonyl carbon bond is indicated as the initial step. Acylcarbon-oxygen, sigma bond homolysis also occurs but rapid decarbonylation ultimately leads to the same indicated products.

Finally, a few miscellaneous compounds which were identified in the Delaware River and which have not been previously reported as water contaminants will be discussed Chloro (trifluoromethyl) aniline and chloro (trifluoromethyl) nitrobenzene (no. 55 and 56) were identified in the water, they had maximum concentrations at river mile 78. Both compounds represent common sub-structures in various pesticide and dye molecules, and several of the companies located along the river have patents using these compounds (30-32j. It is possible that these compounds are actually present in the river water as such, but it is also possible that they are formed in the GC injection port by pyrolytic degradation of larger pesticide or dye molecules (see above). All three binaphthyl-sulfone isomers (no. 92) were identified in the river water near Philadelphia. Product literature for one of the companies in the area indicates production of condensed sulfonated polymers derived from naphthalene sulfonic acid and maleic anhydride. It seems likely that the binaphthylsulfones are formed as by-products during preparation of this commercial product. 

Indications Product name Active ingredient Structure-forming excipients... 

Fig. 36. Removal of byproduct H2S between stages increases HDS reactivity in sequential reactors (second-stage conditions 360DC, 2.9 MPa, 30 min residence time). ( ) Desulfurization performance in normally sequenced stages (O) desulfurization performance when H2S is removed between stages. Zero time indicates product composition after the first stage at 360°C, 2.9 MPa, and 30 min residence time. Figure modified and reproduced with permission from Ref. 14. Copyright 1994 American Chemical Society.

Conversions, mole % of TME to the indicated products. c Unidentified high boiling by-products also formed in 5-10% yield. 

Classify each of the following reactions from the standpoint of yield, side reactions, and reaction rate as good, fair, or bad synthetic procedures for preparation of the indicated products under the given conditions. Show your reasoning and designate any important side reactions. 

Evaluate (show your reasoning) the possibility that the following reaction will give the indicated product ... 

If you do not think the indicated product would be important, write the structure(s) of the product(s) you think would be more likely to be found. 

Show how you would convert each of the following alcohols to the indicated products. Specify necessary reagents and conditions. 

The mechanism of this oxygen transfer involves attack of the amine oxide on a coordinated carbonyl to yield the indicated products, with the resulting vacant coordination site again being filled by a carbonyl. 

Protonation of a carbonyl oxygen rather than the metal may be encouraged in this case by the high coordination number of vanadium. This would then promote halide attack on the carbonyl carbon to yield an intermediate hydroxyhalocarbene, which reacts further to yield the indicated products. This system represents a potential photoassisted water-gas shift catalyst system since H3V(CO)3(diars) upon photolysis with a mercury vapor lamp yields H2, and in the presence of CO regenerates the starting complex HV(CO)4(diars). The feasibility of coupling these two reactions in the same reaction solution remains to be demonstrated. 

A more reliable means of providing a reference of -OH in a biological system maybe by means of irradiation with ionizing radiation (von Sonntag et al. 2000). The action of ionizing radiation on an aqueous medium gives rise to OH whose yield/dose relationship (G value) is known (Chap. 2). Apart from this, since biological media are concentrated solutions the formation of the indicator product, e.g., a phenol (ArOH), via the direct effect [expressions (69) and (70)] must in principle be taken into account as well. It can be shown that with k4i [probe]/ k42 [cellular components] above 10 4 the direct effect contributes less than 10%... 

A-ll. Using curved arrows and perspective drawings (of chair cyclohexanes), explain the formation of the indicated product from the following reaction ... 

To convert the designated starting material to the indicated product, both the nitro group and the... 

Reagents. Give the structure of the major products (A-H) expected from the following reactions. Be sure to indicate product stereochemistries. Assume that standard aqueous workup conditions are used for product isolation. 

Reagents. Give the structures of the intermediates obtained in each step and the final major product expected for each of the following reaction sequences. Be sure to indicate product stereochemistry where applicable. 

---