Conversion tables chemical substitutions

Balanced Alkali is a proprietary chemical of Eastman Kodak, and until recently it was known as Kodalk . Balanced Alkali is more alkaline than borax and more easily soluble, but less alkaline than carbonate. As Balanced Alkali contains no free carbonate, there is no danger of carbonic gas bubbles being formed when an acid stop bath is used (see the next section, Moderate Alkalis). Balanced Alkali can be substituted for carbonate (Conversion Tables Alkali Substitutions), and for almost all purposes it is identical to sodium metaborate. 

In many applications tantalum can be substituted for platinum and gold, and there are some environments in which tantalum is more corrosion resistant than platinum. Table 3.37 lists the main chemicals for which tantalum is not a suitable substitute for platinum and, conversely, those for wliich tantalum is better than platinum. Tantalum is rapidly embrittled by nascent hydrogen even at room temperature. Therefore, it is very important to avoid the formation of galvanic couples between tantalum and other metals. 

Several factors contribute to the frequent use of (3 )-substituted allylic alcohols (13) for asymmetric epoxidation (a) The allylic alcohols are easily prepared (b) conversion to epoxy alcohol normally proceeds with good chemical yield and with better than 95% ee (c) a large variety of functionality in the (3E) position is tolerated by the epoxidation catalyst. Representative epoxy alcohols (14) are summarized in Table 6A.4 [2,4,18,41-53] and Figure 6A.3 (4,54-61], with results divided arbitrarily according to whether the (3E) substituent is a hydrocarbon (Table 6A.4) or otherwise (Fig. 6A.3). The versatility of these and other 3-substi-tuted epoxy alcohols for organic synthesis is illustrated with several examples in the following discussion. 

In general, traditional electrode materials are substituted by electrode superstructures designed to facilitate a specific task. Thus, various modifiers have been attached to the electrode that lower the overall activation energy of the electron transfer for specific species, increase or decrease the mass transport, or selectively accumulate the analyte. These approaches are the key issues in the design of chemical selectivity of amperometric sensors. The long-term chemical and functional stability of the electrode, although important for chemical sensors as well, is typically focused on the use of modified electrodes in energy conversion devices. Examples of electroactive modifiers are shown in Table 7.2. 

Best results were obtained when HFIP (42) was added. Furthermore, this conversion is very clean and 2,4-dimethylphenol (37) is transformed to 38 in 47% yield. Application of abundant electric current renders a lower yield and product quality of 38. A trifluoromethyl group of the additive can be substituted by a phenyl moiety in order to stabilize the oxyl spin center. Therefore, alcohol 43 provides results similar to the additive HFIP. In conclusion, the chemical yield reached about 50%, a maximum when a current of 1—1.3 F was applied per mole 37 and represents a reasonable compromise between yield and current efficiency [27] (Scheme 19) (Table 2). 

Fructose Sugar obtained Irom certain trulls or from the chemical conversion of dextrose (glucose). As 3 substitute for table sugar, because it is sweeter and loss Is needed. Same ealoric and carbohydrate values as mo other pure srrgars. There Is little evidence lo support the use ot fructose tp treating blood sugar disorders. 

In addition to being catalysts for triphasic cyanation reactions, organo hectorite assemblies catalyze a variety of other nucleophilic substitution reactions. Equations 2-6 below illustrate the diverse range of reactions that can be catalyzed by [(n-CgHi7)3NMe]+- hectorite. Reaction conditions and chemical yields for each conversion are provided in Table II. 

The conversion and selectivities to toluene and benzene were determined after Ih of reaction, when nearly steady-states were reached. Table 1 shows the influence of chemical composition on catalytic properties of CaTiOs and substituted perovskites on benzaldehyde conversion reaction. Compared to CaTiOs, the substituted perovskites are less active under H2 flow and the benzaldehyde conversion decreases with the increasing of Ca substitution by Mg in the following order ... 

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