Parallel synthesis, description

The main aspects of the preparation of discrete libraries on SP will be covered in the first section, which will deal with the area of so-called parallel synthesis and discuss its application to different chemical problems. The choice of manual versus automated or semiautomated parallel synthesis will also be discussed through the detailed description of selected examples. 

In addition, several articles on microwave-assisted parallel synthesis have described irradiation of 96-well filter-bottom polypropylene plates in conventional household microwave ovens for high-throughput synthesis [16-19]. One interesting article described the construction and use of a parallel polypropylene reactor comprising cylindrical, expandable reaction vessels with porous frits at the bottom [20]. This work presented the very first description of reaction vessels for microwave-assisted synthesis that may be useful for performing solid-phase synthesis using bottom-filtration techniques in conjunction with microwave heating. 

In another report, aspects for automating preparative chemistry are described [130]. A comprehensive description of the Ugi reaction is given in [132] and the vision of a micro multi-component reaction as automated parallel micro-channel synthesis is sketched. An interesting point is to convert aldehydes, chiral primary amines, carboxylic adds and isocyanates into corresponding a-amino acids and peptides (U-4CR). 

The synthesis of block and graft copolymers by mechanical forces has bear earlier reviewed by many authors (4-10). This review is thus not intended to be exhaustive and a different approach has thus been takea The material is organized by state of matter rather than by the instruments used. Thus the authors hope to provide a descriptive mosaic for the parallel studies developing in different countries and in different facets of the field. Some of the original references may be difficult to procure so that more general secondary references are cited in some cases. 

The amphetamine homologue of proscaline, 3,5-dimethoxy-4-(n)-propoxy-amphetamine is an unexplored compound. Its synthesis could not be achieved in parallel to the description given for P. Rather, the propylation of syringaldehyde to... 

Fig. 1. Luther R. Hill s sketch of June 14, 1946, proposing a circulating-fluid-bed reactor for gasoline synthesis. The arrangement is a poor idea (see Section III for description of troubles that Sasol encountered in operating the heat exchangers depicted in Fig. 4, which also required gas and powder to flow upward via parallel paths).

Raul Camposano, Amo Kunzmann, and Wolfgang Rosenstiel, Automatic Data Path Synthesis from Behavioural Level Descriptions in DSL , in VLSI Algorithms and Architectures (Proc. of the Int. Workshop on Parallel Computing and VLSI, May, 1984), P. Bertolazzi and F. Lucdo (Editors), pages 23 242, North Holland, 1985. 

MCM-41 is the well known model mesoporous material containing extended hexagonal arrays of parallel tubular pores separated by amorphous silica (Fig. 1.). This is a common description, on the heise of most studies to interpret adsorption phenomenon results. However, the structural and chemical parameters of the host porous material have a crucial influence on the adsorption mechanism. Actually each synthesis produces MCM-41 sample with its own silica wall and porosity. Our MCM-41 (19 A < 0 < 40 A) samples have been extensively characterized by sorption isotherm, microcalorimetry and neutron diffraction measurements... 

The objective of behavioral synthesis is to identify as much parallelism as possible in the input description. This gives an indication of the fastest design that the system can produce, assuming that in the design implementation each operation is implemented by a dedicated hardware component. While this assumption may not be realistic in some cases due to area and interconnection costs, it is important to compute the related performance as a limiting bound for a given behavior. 

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