Dicarboxy-addition

Azobenzol kann mit guter Ausbeute im Kohlendioxid-Strom reduktiv unter C02-Addition zum 1,2-Diphenyl-l,2-dicarboxy-hydrazin reduziert werden (geteilte Zellc)3 ... 

If the polyester synthesis is performed with equimolar amounts of diol and diacid, then, in addition to hydroxy, carboxy-terminated oligomers, dihydroxy- and dicarboxy-terminated oligomers are formed, as shown below. In a thermodynamic equilibrium, the molar ratios of the three functionality fractions should be 2 1 1, respectively. 

If one substituent at C-6 in the starting fulvenes incorporates a stereogenic center, e.g., at C-7, two diastereomers are produced in a similar amount upon addition of diazene dicarboxy-lates at either face of the dienel2,13. 

Bredereck and Schmotzer (1044), from diaminomaleonitrile (DAMN hydrogen cyanide tetramer) and oxalyl chloride, prepared 2,3-dicyano-5,6-dihydroxy-pyrazine but Stetten and Fox (1049) could not prepare 23-diamino-5-hydroxy-pyrazine from glycine amide and oxamide. Section 11.3 lists preparations from a, -diamino or a, -diimino compounds and reagents other than a,0-dicarbonyl compounds (384) with additional data (1050) and oxidation of 23-dichloro-quinoxaline with hot aqueous potassium permanganate gave 23-dicarboxy-5,6-dihydroxypyrazine (1051). 

Experimental. The general conditions of experiments, and methods of investigations were similar to those described previously.However, extremely precise and reproducible results of crosslinking were achieved owing originally developed device for exposure (Pig in which the specimens may be rotated with chosen rate. Additionally, the selection of UV-sensitizers was ex-tented, and besides diphenyl sulphoxide, also dinaphtyl sulphoxide, methyl - benzyl sulphoxide, bis- p-chloro-phenyl sulphoxide, bis- 2,4-dichlorophenyl sulphoxide, were used. Also, some other compounds were examined, namely diphenyl sulphide and its p-nitro-p-amino- as well o,o-dicarboxy-derivatives, methiomethy-lene-diethyl phosphate and uranyl acetate. 

The photoactivity of the Pt/Ti02 system in the visible region was improved [208] by the addition of the sensitizer ([Ru(dcbpy)2(dpq)]2+) [where dcbpy = 4,4 -dicarboxy 2,2 -bipyridine and dpq = 2,3-bis-(2 -pyridyl)-quinoxaline] leading to an efficient water reduction. 

Anhydrides of cis-cyclopropane-1,2-dicarboxy lie acids are converted to CM-2-acylcyclo-propanecarboxylic acids using various reagents. The outcome of the reaction is sensitive to the reaction conditions. Treatment of c i-3-oxabicyclo[3.1.0]hexane-2,4-dione with phenylmag-nesium bromide at low temperature" and dimethylcadmium at room temperature gave c/s-2-benzoyl- and c -2-acetylcyclopropanecarboxylic acid in 53 and 70% yield, respectively in addition minor amounts of disubstituted lactones were formed. 1129,1251 jjowever, no lactone was formed when cis-2-benzoylcyclopropanecarboxylic acid was prepared in 66% yield by reacting c -3-oxabicyclo[3.1.0]hexane-2,4-dione with benzene under Friedel-Crafts conditions." ... 

Thus, we investigated in detail the factors influencing intramolecular addition modes in the radical cyclopolymerization of some unconjugated dienes, including diallyl and dimethallyl dicarboxy-lates, acrylic and methacrylic anhydrides, and allyl -substituted acrylates and discussed the selectivity of reaction mode of intramolecular hh or ht addition in terms of the thermodynamical standpoint. The present article gives a summary of our recent work including published papers(18-23). 

Pyrolysis and smoke studies of amino acids indicate that they are potential precursors of several nitrogen heterocyclic ring systems found in tobacco smoke. Proline has been shown to be efficiently converted to pyrrole upon pyrolysis (3219, 3724) and in addition has been proposed as a possible precursor of pyrocoll (2593, 4336). y-Amino acids and dicarboxy-lic amino acids are capable, under pyrolytic conditions, of forming 2-pyrrolidones (1967, 3079) and by a similar mechanism, A-amino acids can form 2-piperidones (1967, 3079). A side effect of the pyrolysis of amino acids is the formation of hydrogen cyanide. 

This chapter covers fundamental and applied research on polyester/clay nanocomposites (Section 31.2), which includes polyethylene terephthalate (PET), blends of PET and poly(ethylene 2,6-naphthalene dicarboxy-late) (PEN), and unsaturated polyester resins. Section 31.3 deals with polyethylene (PE) and polypropylene (PP)-montmorillonite (MMT) nanocomposites, including blends of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE). Section 31.4 analyzes the fire-retardant properties of nanocomposites made of high impact polystyrene (HIPS), layered clays, and nonhalogenated additives. Section 31.5 discusses the conductive properties of blends of PET/PMMA (poly (methyl methacrylate)) and PET/HDPE combined with several types of carbon... 

The n.m.r. spectra of a number of mono- and di-substituted selenophens have been analysed and the chemical shifts discussed in additivity terms. An A%ray analysis of racemic 4,4 -dicarboxy-2,2, 5,5 -tetramethyl-3-3, -biselenienyl has been carried out. Dipole moments and u.v. spectra of chalcone analogues containing a selenophen ring have been studied. 

The citrate route to colloidal Au, first described by Hauser and Lynn [164], is a popular method to prepare Au hydrosols. Synthesis by the citrate method involves the addition of chloroauric acid to a boiling solution of sodium citrate [144]. A wine red color indicates the onset of reduction. The average diameter of the nanoparticles can be varied over a range of 10-100 nm by varying the concentration ratio between chloroauric acid and sodium citrate (see Fig. 2.4). Turkevich [165] proposed that the reaction involved the formation of acetone dicarboxylate. Subsequent reduction occurs by the dicarboxy-late species. The citrate method has been extended to synthesize of Pt and Ag nanoparticles [166-168]. Turkevich and coworkers [169] prepared Au-Pt... 

A polymer complex containing Ru(bpy)3 pendant groups was obtained by the reaction of a lithium substituted polystyrene with 2,2 -bipyridyl followed by interaction with c/>Ru(bpy)2 [131]. Another example is binding of 4,4 -dicarboxy-2,2 -bipyridyl at a copolymer of />-aminostyrene followed by reaction with c/>Ru(bpy)i (structure 19) [132]. Other copolymers with pendant Ru(bpy)3 bound via a spacer or containing additional bound 4,4 -bipyridyl are also prepared. These materials are interesting as sensitizers for visible light energy conversion. 

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