Preparation and reactions

Although 6,7-dihydro-5/7- 1-pyrindine (10) and its derivatives have been known for years,1-8 the first unsubstituted 5/7- 1-pyrindine (7) was not prepared until 1958. Attempts to dehydrogenate 10 with selenium at 400° or with palladium-charcoal at 350° were unsuccessful.10 

Harrison, Ph.D. Thesis, University of Washington, Seattle, Washington, 1960. 

Albert, Heterocyclic Chemistry, An Introduction. Athlone Press, London, 1968. 

Franke, V. Horak, I. Hanker, and R. Zahradnik, Tetrahedron Lett., 289(1961). 

Although a plausible mechanism for the rearrangement of 15 to 16 is shown below,27a-29b an alternative free radical30a-30d or cyclic intramolecular mechanism is also reasonable.291 

The aldonic acids are the initial oxidation products produced from aldoses by most oxidants and are usually isolated as the metallic salts or the lactones. As a result of the ease with which the crystalline lactones, salts, amides, hydrazides, and other derivatives can be formed, aldonic acids are 

The aldonic acids, especially gluconic acid in the form of soluble salts, are important as cation sequestering agents for the purpose of introducing appropriate metallic ions such as iron, bismuth, and particularly calcium into the body in a neutral and easily assimilable form. Calcium lactobio-nate CaBr2 may have value as a sedative. 

These acids are important precursors in the preparation of sugars with fewer carbon atoms. Oxidative degradation with H2O2 and iron salts (see p. 118) produces an aldose of one less carbon atom thus, D-gluconic acid is converted to D-arabinose, and D-galactonic acid to D-lyxose. Nitriles and amides can also be degraded (see p. 119). 

Methods for lengthening the carbon chains of sugars may involve the formation of aldonic acids as intermediates. The Kiliani cyanohydrin synthesis (see p. 106) creates two new aldonic acids with one more carbon atom than in the original aldose. The configuration of the new asymmetric atom can be assigned by use of the lactone rule discussed below. 

Finally, an aldonic acid can be converted to its 2-epimer by the action of alkaline agents (see below). 

Beilstein is not a specific database for reactions, but nevertheless it contains more than 550,000 reactions and 4.5 million preparations. True reaction databases, eg. CASREACT, Cheminform RX and Chemreact contain only recent data. Beilstein and Gmelin (Sect. 7.11) cover the period back to the 18th century. 

Search for preparation processes as well as reactions must be done in order to retrieve the complete range of reactions in Beilstein. The preparation of a substance is recorded in the field Preparation (PRE). This field is separated into the search fields (subfields)  

Reactions are found in the field Reaction (REA), which is equally separated into  

When starting the search with a substance name but without restriction to a certain field, automatically all the six subfields mentioned above and the fields Chemical Name (CN) and Synonyms (SY) are searched by the system. 

To retrieve information about the preparation of a compound (Figs. 150 and 151) the following searches must be done  

Meister, Enzyme-Act. Irreversible Inhibitors, Proc. Int. Symp., 1978, 187 (Chem. Abstr. 1980,92, 71 523). 

Several other jV-sulphinyl-amines or -amides can be prepared or generated, without isolation, and added to olefins,ketones, or enamines and ynamines. Similarly, A -sulphinyl-sulphonamides (1) and sulphinyl-amines (2 Ar = Ph or P-NO2C6H4) react with hexafiuoroacetone or polyfiuoro-olefins in aprotic solvents in the presence of CsF [see reactions (1) and (2)1, affording, directly, the imino-compounds these are undoubtedly formed via initial formation of the [2 + 2]-cyclo-adducts.  

New metal—R insertion complexes between [( / -CjH5)Fe(CO)2Rl (R = alkyl or aryl) and (1) or sulphur di-imides have been reported. TTie photolysis of JV-phenyl-JV -sulphinylhydrazine in aromatic solvents generates phenyl radicals these undergo addition to the solvents, affording biphenyls.  

JV-Thiosulphinyl-amines (6) or -anilines (7 R = N=S=S) have been prepared 

Moriyama, T. Yoshioka, and T. Nishimura, Japan. Kokai 78 124 273. 

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This chapter concerns the preparation and reactions of acyl chlorides acid anhydrides thioesters esters amides and nitriles These com pounds are generally classified as carboxylic acid derivatives and their nomenclature is based on that of carboxylic acids... 

Contents Introduction and Principles. - The Reaction of Dichlorocarbene With Olefins. - Reactions of Dichlorocarbene With Non-Olefinic Substrates. -Dibromocarbene and Other Carbenes. - Synthesis of Ethers. - Synthesis of Esters. - Reactions of Cyanide Ion. - Reactions of Superoxide Ions. - Reactions of Other Nucleophiles. - Alkylation Reactions. - Oxidation Reactions. - Reduction Techniques. - Preparation and Reactions of Sulfur Containing Substrates. -Ylids. - Altered Reactivity. - Addendum Recent Developments in Phase Transfer Catalysis. 

Donald J Burton and Jerry L Halinfeld, The Preparation and Reactions of Fluoromethylenes... 

Preparation and Reactions of Polyfluorinated Aromatic Heterocyclic Compounds Yakobson G G, Petrova, T D, Kobnna, L S Fluorine Chem Rev 7, 115-223 285... 

The Preparation and Reactions of Fluoromethyleiies Fluorinated Isocyanates and Their Denvatives as Intermediates for Biologically Active Stibsianccs (Ccr) Radical Reactions of Polyfliioroaromatic Compounds (Russ )... 

Preparations and reactions of inorganic main-group oxide fluorides. J. H. Holloway and D. Lay-cock, Adv. Inorg. Chem. Radiochem., 1983,27,157-195 (342). 

This section covers the preparation and reactions of quinoxalinecarboxylic esters, generally the most convenient derivatives of quinoxalinecarboxylic acids. 

In the present study, catalysts containing 0.5 wt% transition metals were prepared and reaction was carried out. The results of these studies are presented in Fig. 3. In screen test of various transition metals loaded AC catalysts acetone was used as the solvent. It was also found that Fe containing catalyst gave the highest yield of phenol. Hence, for further study catalysts containing Fe loaded on activated carbon were chosen. 

Uson, R., Laguna, A. and Bergareche, B. (1980) Dihalopentafluorophenyl-tetrahydrofhiophenegold(III) complexes, their preparation and reactions. Journal of OrganometaUic Chemistry, 184(3), 411 16. 

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