Patent, selection type

Although acrylonitrile manufacture from propylene and ammonia was first patented in 1949 (30), it was not until 1959, when Sohio developed a catalyst capable of producing acrylonitrile with high selectivity, that commercial manufacture from propylene became economically viable (1). Production improvements over the past 30 years have stemmed largely from development of several generations of increasingly more efficient catalysts. These catalysts are multicomponent mixed metal oxides mostly based on bismuth—molybdenum oxide. Other types of catalysts that have been used commercially are based on iron—antimony oxide, uranium—antimony oxide, and tellurium-molybdenum oxide. 

A recent patent application from Roche [352] described a 2-amino-benzothiazole series. Roche claimed that compound (605) exhibited an IC50 value of 0.73 uM at CBi, and showed in excess of 10-fold selectivity over the CB2 receptor. The compounds were described as being of potential use in the treatment of a range of diseases, including CNS and psychiatric disorders, type-2 diabetes, gastrointestinal diseases, cardiovascular disorders, infertility disorders, inflammation, cancer, atherosclerosis, cerebral vascular incidents and cranial trauma. 

The first wave-dispersion-type screw was developed and patented by Kruder in 1975 [18], and the device was trademarked as the Wave screw. Numerous other wave dispersion screws were developed later based on Kruder s design. The term wave dispersion screw refers to screws with metering sections that have two or more channels with a flight between them that is selectively undercut to allow the dispersion of solid polymer fragments and molten resin. Several commercially available screws utilize this type of technology and are discussed in this section. These screws include Double Wave screws, Energy Transfer screws. Variable Barrier Energy Transfer screws, DM2 screws, and Fusion screws. 

The third and last part of the book (Chapters 12-16) deals with zeolite catalysis. Chapter 12 gives an overview of the various reactions which have been catalyzed by zeolites, serving to set the reader up for in-depth discussions on individual topics in Chapters 13-16. The main focus is on reactions of hydrocarbons catalyzed by zeolites, with some sections on oxidation catalysis. The literature review is drawn from both the patent and open literature and is presented primarily in table format. Brief notes about commonly used zeolites are provided prior to each table for each reaction type. Zeolite catalysis mechanisms are postulated in Chapter 13. The discussion includes the governing principles of performance parameters like adsorption, diffusion, acidity and how these parameters fundamentally influence zeolite catalysis. Brief descriptions of the elementary steps of hydrocarbon conversion over zeolites are also given. The intent is not to have an extensive review of the field of zeolite catalysis, but to select a sufficiently large subset of published literature through which key points can be made about reaction mechanisms and zeolitic requirements. 

In our review we present general and specific examples of all these three types of MCRs, which involve aminoazoles as 1,3-binucleophile reagents. In the following sub-chapters, the most part of published original articles and selected patents in this topic will be observed and discussed. 

Much progress has been made in understanding the catalytic activity of zeolites for several type of reactions. The number of reactions catalyzed by zeolites has been extended, and new multi-component polyfunctional catalysts with specific properties have been developed. In addition to cracking and hydrocracking, reactions such as n-alkane isomerization, low temperature isomerization of aromatic C8 hydrocarbons, and disproportionation of toluene are industrially performed over zeolite-containing catalysts. Moreover, introduction of various compounds (C02, HCl) into reaction mixtures allows one to control the intensity and selectivity of the reactions. There are many reviews on the catalytic behavior of zeolites and even more original papers and patents. This review emphasizes the results, achievements, and trends which we consider to be most important. 

Difluorobenzenes are isomerized under gas-phase conditions in the presence of metallosilicates, containing the structure of pentasil zeolites with isomorphic substitution of some silicon atoms by aluminum, gallium, or iron.4 A German patent describes the isomerization of l-bromo-2,4-difluorobenzene to l-bromo-3,5-difluorobenzene in pentasil-type zeolites in an autoclave at 320 C and 25 x 105 Pa for 1 h, giving 29% conversion and 73% selectivity.5... 

Transition metal sulphides are able to catalyze a very large number of reactions. The most important utilization concerns catalytic hydrotreating, but many others can be foreseen due to the resistance of these catalysts towards sulphur. For example, recent studies have demonstrated the interest of such catalysts for the selective conversion of carbon monoxide into hydrocarbons [1] or alcohols [2]. Until now, only few papers and patents report on the utilization of sulphides for fine chemical applications [3-6]. Nevertheless, this type of solids fits well to catalyze the reactions dealing with sulphur containing molecules. 

H2 conversion was also typically lower than total, ranging from 30 to 70%. A H2 recycle is thus necessary. Staged (sequential) addition of H2 to maintain a more uniform 02 H2 ratio in the reactor and avoid excess 02 has also been shown to improve performances. Batch-type autoclave or continuous fixed bed (trickle-bed) or stirred reactors have been used. Operations were typically under pressure in the 50-100 bar range, again with the exception of the cited CSIR patents. The reaction temperature ranged from 4 to 605 °C. Upon decreasing the temperature, H2 solubility increases, but the catalyst specific activity decreases. The productivity should thus pass through a maximum nevertheless this depends from case to case. Table 8.3 summarizes selected results from recent patents. 

Various studies and some patents have been published on the use of membrane catalysts for the direct synthesis of H202 [73-81]. The redox treatment of the membrane influences the properties both in the synthesis and decomposition of H202. Formation of a hydrophobic layer improves the selectivity, because it limits the consecutive decomposition of hydrogen peroxide, limiting the chemisorption of H2 and re-adsorption of H202 [73]. Either polymeric or ceramic-type membranes could be used, but the latter are preferable to allow more robust operations. The mono- or bi-metallic Pd-based active component could be deposited either in the form of dispersed particles (e.g., by precipitation-deposition) or of a thin film (e.g., by... 

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