First Chemical

Structural drawings of carbohydrates of this type are called Haworth formulas, after the British chemist Sir Walter Norman Haworth (St Andrew s University and the University of Birmingham) Early m his career Haworth contributed to the discovery that carbohydrates exist as cyclic hemiacetals rather than m open chain forms Later he col laborated on an efficient synthesis of vitamin C from carbohydrate precursors This was the first chemical synthesis of a vitamin and provided an inexpensive route to its prepa ration on a commercial scale Haworth was a corecipient of the Nobel Prize for chem istry m 1937... 

Eastman Goal Chemicals. In 1983 Eastman Chemical Co. became the first chemical producer in the United States to return to coal as a raw material for large-scale manufacture of industrial chemicals (35). In that year, Eastman started manufacturing acetic anhydride from coal. Acetic anhydride is a key intermediate for production of coatings, ceUulosic plastics, and cellulose acetate fibers. Acetic anhydride from other sources also is used in the manufacture of pharmaceuticals, starches and sweeteners, and flavors and fragrances. 

Chemiluminescent Immunoassay. Chemiluminescence is the emission of visible light resulting from a chemical reaction. The majority of such reactions are oxidations, using oxygen or peroxides, and among the first chemicals studied for chemiluminescence were luminol (5-amino-2,3-dihydro-l,4-phthalazinedione [521-31-3]) and its derivatives (see Luminescent materials, chemiluminescence). Luminol or isoluminol can be directly linked to antibodies and used in a system with peroxidase to detect specific antigens. One of the first appHcations of this approach was for the detection of biotin (31). 

Because the highest possible interfacial area is desired for the heterogeneous reaction mixture, advances have also been made in the techniques used for mixing the two reaction phases. Several jet impingement reactors have been developed that are especially suited for nitration reactions (14). The process boosts reaction rates and yields. It also reduces the formation of by-products such as mono-, di-, and trinitrophenol by 50%. First Chemical (Pascagoula, Mississippi) uses this process at its plant. Another technique is to atomize the reactant layers by pressure injection through an orifice nozzle into a reaction chamber (15). The technique uses pressures of typically 0.21—0.93 MPa (30—135 psi) and consistendy produces droplets less than 1 p.m in size. The process is economical to build and operate, is safe, and leads to a substantially pure product. 

The acidic contaminants can also be removed by employing a system that utilizes extractions, precipitation, distillation, and other treatments for rendering the waste stream acceptable for current disposal standards (18—20). First Chemical Corporation uses such a system. Residual nitric acid can be removed by a multistage countercurrent Hquid-Hquid extraction. The nitric acid (ca 25%) is then reconcentrated by distillation for further use. 

First Chemical Corporation, Du Pont, BASF Corporation, and Bayer Corporation (formerly Miles, Inc). ... 

Economic Aspects. Annual 1993 U.S. production of the mononitrotoluenes is 26,000 metric tons, with about 16,120 metric tons of the ortho isomer, 780 metric tons of the meta isomer, and 9,100 metric tons of the para isomer. The prices of (9-, m-., and -nitrotoluene in bulk fob are 1.15/kg, 2.54/kg, and 3.64/kg, respectively. The mononitrotoluenes are manufactured by Du Pont and First Chemical Corp. 

Atistech Chemical Du Pont First Chemical Mobay Rubicon... 

Because of the time and expense involved, biological assays are used primarily for research purposes. The first chemical method for assaying L-ascorbic acid was the titration with 2,6-dichlorophenolindophenol solution (76). This method is not appHcable in the presence of a variety of interfering substances, eg, reduced metal ions, sulfites, tannins, or colored dyes. This 2,6-dichlorophenolindophenol method and other chemical and physiochemical methods are based on the reducing character of L-ascorbic acid (77). Colorimetric reactions with metal ions as weU as other redox systems, eg, potassium hexacyanoferrate(III), methylene blue, chloramine, etc, have been used for the assay, but they are unspecific because of interferences from a large number of reducing substances contained in foods and natural products (78). These methods have been used extensively in fish research (79). A specific photometric method for the assay of vitamin C in biological samples is based on the oxidation of ascorbic acid to dehydroascorbic acid with 2,4-dinitrophenylhydrazine (80). In the microfluorometric method, ascorbic acid is oxidized to dehydroascorbic acid in the presence of charcoal. The oxidized form is reacted with o-phenylenediamine to produce a fluorescent compound that is detected with an excitation maximum of ca 350 nm and an emission maximum of ca 430 nm (81). 

Zirconium tetrafluoride [7783-64-4] is used in some fluoride-based glasses. These glasses are the first chemically and mechanically stable bulk glasses to have continuous high transparency from the near uv to the mid-k (0.3—6 -lm) (117—118). Zirconium oxide and tetrachloride have use as catalysts (119), and zirconium sulfate is used in preparing a nickel catalyst for the hydrogenation of vegetable oil. Zirconium 2-ethyIhexanoate [22464-99-9] is used with cobalt driers to replace lead compounds as driers in oil-based and alkyd paints (see Driers and metallic soaps). 

Salt has had a significant impact on the economies of some countries, and in some places it stUl does. Salt was the first chemical recognized and used in ancient times (69). It was first used in food for taste enhancement and as a preservative (see SoDlUMCOMPOUNDS). 

Chemoinformatics (or cheminformatics) deals with the storage, retrieval, and analysis of chemical and biological data. Specifically, it involves the development and application of software systems for the management of combinatorial chemical projects, rational design of chemical libraries, and analysis of the obtained chemical and biological data. The major research topics of chemoinformatics involve QSAR and diversity analysis. The researchers should address several important issues. First, chemical structures should be characterized by calculable molecular descriptors that provide quantitative representation of chemical structures. Second, special measures should be developed on the basis of these descriptors in order to quantify structural similarities between pairs of molecules. Finally, adequate computational methods should be established for the efficient sampling of the huge combinatorial structural space of chemical libraries. 

To use the volume effectively, the reader should first review the Glossary of Terms section immediately preceding the first chemical entry. This section contains precise definitions used for certain parameters where data have been obtained for each chemical. A review of these terms will help the reader interpret certain information. In addition, a list of abbreviations used throughout the volume is also provided in the front section of the handbook. 

It is of interest to note that rhyncophylline occurs in two genera, Mitragyna and Ourouparia. Raymond-Hamet suggested in 1936 that rhyncophylline, hanadamine and formosanine are chemically and pharmacologically related to the Mitragyna alkaloids and the first chemical evidence of this is the identification of mitrinermine with rhyncophylline (Barger et al.). Millat has recently expressed doubt of this identification. 

Fire Retardant Chemical Association, 271 First Chemical Corporation, 223 Fhst Chemical Inc., 228 Fhst Quantum Minerals Ltd., 148 FLAME PLUS , glyphosate, 69 Fleming Laboratories Inc., 228 Fleurchem hic., 228... 

J. S. Elsholtz described emission of bluish-white light when fluorspar was heated. Also described by J. G. Wallerius, 1750 the name fluorescence was coined in 1852 by G. G. Stokes 1768 First chemical study of fluorite undertaken by A. S. Marggraf... 

The first chemical synthesis of these substances, using a procedure which yields 1-ribofuranosyl derivatives by pyrimidine bases, was described by Hall. By using the mercuric salt of 6-azathymine and tribenzoate of D-ribofuranosyl chloride, he obtained a mixture of two monoribosyl derivatives and a diribosyl derivative. He determined the structure of the 3-substituted derivative by the similarity of spectra and other properties to those of 3-methyl-6-razauracil. The structure of the 1-ribosyl derivative was then determined from the similarity of the spectra with 6-azathymine deoxyriboside obtained enzymatically. 

John Winthrop, Jr., opens America s first chemical plant in Boston. They produce saltpeter (used m gunpowder) and alum (used in tanning). 

The fragility of this natural product notwithstanding, S.J. Danishefsky and his group at Yale disclosed, in 1-990, the first chemical synthesis of racemic indolizomycin (1).2 The construction of such a vulnerable substance in the laboratory is a most admirable achievement. The remainder of this chapter is devoted to Danishefsky s elegant total synthesis of ( )-indolizomycin [( )-1],... 

Historically the Strecker synthesis of a-amino acids constitutes the first chemical access to this important class of compounds1, In this process, an aldehyde reacts with ammonia and hydrogen cyanide to form an a-amino nitrile2 which subsequently is hydrolyzed to give the corresponding amino acid3... 

We can now deal with certain special cases. If the first relaxation time is much shorter than the second, then the first chemical step is faster than the second. In that case... 

The hrst mechanism specihcally for tungsten CMP was proposed by Kaufman et al. [67]. They thought, first, chemical action dissolves W and forms a very thin passivating him which stops growth as soon as it reaches a thickness of one or a few moleculars later. Second, the him is removed locally by the mechanical action of abrasive particles, which contact with the protrude parts of the wafer surface, and then cause material loss. In recent years, most of the analysis and models for metal CMP are built based on the Kaufman model [68,69]. However, the model is not involved in microscopic structure analysis for the polished surface, but focuses on interpreting macroscopic phenomena happening during CMP [18]. 

Lime has been manufactured for more than 2000 years and was the product of one of the first chemical processes used in the U.S. by the early settlers (the manufacture of rum being another). The many uses of lime are so varied that limestone and lime production are greater than any other natural substance. It is a low-cost commodity in the U.S. because there are limestone deposits in many parts of the country. Lime plants are always close to the limestone source in order to minimize freight costs. 

BASF, Bayer, DuPont, Huntsman, First Chemical. 

One of the first chemical applications of radioactive tracers was a set of elegant experiments on photosynthesis performed in the 1950s by Melvin Calvin. His goal was to determine the set of reactions used by plants to transform atmospheric CO2 into carbohydrates. Calvin supplied growing plant cells with CO2 enriched with 14... 

We developed and applied two oxidation methods to lycopene and p-carotene. The first chemical oxidation method was performed in biphasic medium using the potassium permanganate hydrophilic oxidant. Cetyltrimethylammoniumbromide was the phase transfer agent used to achieve contact of the hydrophilic oxidant with the lycopene lipophilic carotenoid dissolved in methylene chloride/toluene (50/50, v/v). 

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