Synthesis diamines

Deuterated thiazoles, mass spectra of, 347 Deuterium exchange, in thiazoles, 113 Deuterothiazoles, infrared absorption, 57 7V,A -Diacetyl V,A -bis (4-phenyl-2-thia-zolyhnethyl-ethylene diamine), synthesis of, 195... 

Mallakpour S, Dinari M. Chiral poly(amide-imide)/organoclay nanocomposites derived from pyromelUtoyl-bis-l-isoleucine and benzimidazole containing diamine synthesis, nanostructure, and properties. Colloid Polym Sci 2012 290(l) 81-90. 

The reactor of the Leonard s process for ethylene diamine synthesis is operated at low temperature (< 300°C) and high pressure, probably more than 200 bar. It is so possible than a liquid phase occurs inside the catalytic bed. 

Scheme 16.10 Diamine synthesis within aza-Wacker reactions.

Lin C, Hung WT, Kuo CY, Liao KS, Liu YC, Yang WB (2010) l -catalyzed oxidative condensation of aldoses with diamines synthesis of aldo-naphthimidazoles for carbohydrate analysis. Molecules 15 1340-1353... 

Zanoaga, M. Novel thermoplastic copolyamides based on caprolactam, 1,6-hexane diamine. Synthesis and study of properties. In Proceedings of 12th Romanian International Conference on Chemistry and Chemical Engineering, September 13-15, 2001, Bucurejti, Romania, pp. 125-130... 

Fig. 7 Sulfonated diamine synthesis by aromatic nucleophilic substitution...

Primary and secondary amines also react with epoxides (or in situ produced episulfides )r aziridines)to /J-hydroxyamines (or /J-mercaptoamines or 1,2-diamines). The Michael type iddition of amines to activated C—C double bonds is also a useful synthetic reaction. Rnally unines react readily with. carbonyl compounds to form imines and enamines and with carbo-tylic acid chlorides or esters to give amides which can be reduced to amines with LiAlH (p. Ilf.). All these reactions are often applied in synthesis to produce polycyclic alkaloids with itrogen bridgeheads (J.W. Huffman, 1967) G. Stork, 1963 S.S. Klioze, 1975). 

Synthesis and Properties. Several methods have been suggested to synthesize polyimides. The predominant one involves a two-step condensation reaction between aromatic diamines and aromatic dianhydrides in polar aprotic solvents (2,3). In the first step, a soluble, linear poly(amic acid) results, which in the second step undergoes cyclodehydration, leading to an insoluble and infusible PL Overall yields are generally only 70—80%. 

Polyetherimide synthesis has been achieved by reaction of a dianhydride containing an ether linkage with a diamine, reaction of a diamine containing an ether linkage with a dianhydride, or nucleophilic displacement of halo or nitro groups of a bisimide by bisphenol dianion (19,20). Such Pis exhibit good thermal stabiUty and melt processibiUty. 

Synthesis and Properties. A number of monomers have been used to prepare PQs and PPQs, including aromatic bis((9-diamines) and tetramines, aromatic bis(a-dicarbonyl) monomers (bisglyoxals), bis(phenyl-a-diketones) and a-ketones, bis(phenyl-a-diketones) containing amide, imide, and ester groups between the a-diketones. Significant problems encountered are that the tetraamines are carcinogenic, difficult to purify, and have poor stabihty, and the bisglyoxals require an arduous synthesis. 

Other Preparative Reactions. Polyamidation has been an active area of research for many years, and numerous methods have been developed for polyamide formation. The synthesis of polyamides has been extensively reviewed (54). In addition, many of the methods used to prepare simple amides are appHcable to polyamides (55,56). Polyamides of aromatic diamines and aUphatic diacids can also be made by the reaction of the corresponding aromatic diisocyanate and diacids (57). 

The synthesis of y -phenylenediarnine [108-45-2] is also straightforward it proceeds via the formation of y -dinitroben2ene [99-65-0] by the nitration of ben2ene, followed by hydrogenation to the diamine. 

Syntheses. The presence of the ether and imide functionahties provides two general approaches for synthesis. Polyetherimides can be prepared by a nucleophilic displacement polymerkation similar to the haUde displacement inpolysulfone synthesis or by a condensation of dianhydrides and diamines that is similar to normal polyimide synthesis (see POLYIMIDES). 

The synthesis which forms the basis of production at Hoffmaim-La Roche (Fig. 5) proceeds via the pyrimidinenitrile [698-29-3] (26) made from malononittile, trimethylorthoformate, ammonia, and acetonitrile (42,43). High pressure catalytic reduction of the nitrile furnishes diamine (16). The overall sequence is short, highly efficient, and generates almost no waste. However, malononittile is a relatively expensive and ha2ardous three-carbon source. 

Synthesis. The method of synthesis for Methylene Blue described in reference 14 is stiU the stepwise method of choice for thiazine dyes. /V,/V-Dimethy1-y-pheny1ene diamine [99-98-9], CgH22N2, reacts with sodium thiosulfate [7772-98-7] to form the thiosulfonic acid which condenses with /V, /V-dimetby1 ani1 ine [121 -69-7], CgH N, in the presence of sodium dichromate [10588-01-9] to the indamine, then with copper sulfate [18939-61 -2] and sodium dichromate to Methylene Blue (26). 

Nylon resins are made by numerous methods (53) ranging from ester amidation (54) to the Schotten-Baumann synthesis (55). The most commonly used method for making nylon-6,6 and related resins is the heat-induced condensation of monomeric salt complexes (56). In this process, stoichiometric amounts of diacid and diamine react in water to form salts. Water is removed and further heating converts the carboxylate functions to amide linkages. Chain lengths are controlled by small amounts of monofunctional reagents. The molten finished nylon resin can be dkectly extmded to pellets. 

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