Diaminals formation

It was found that the initial reaction rate was equal to YoAo, where Yo and Ao are the initial concentrations of epoxy groups and m-phenyl diamine. Formation of hydroxyl groups during the reaction leads to self-acceleration. This prediction was confirmed by measurements carried out in an isothermal regime, because adiabatic conditions for a reaction lead to self-acceleration due to an increase in temperature (see above). Thus, the initial reaction rate vo can be expressed as... 

The question is now how is the aziridine 201 formed Until recently, it has been assumed that o-diamine formation is indica-... 

In (6-6)bicyclic aromatic systems photolysis of a-azido compounds in primary aliphatic amines favors azepine formation, while )S-azido compounds form o-diamines. o-Diamine formation again predominates in photolysis of both a- and j -azido(6-6)bicyclic aromatics in secondary aliphatic amines. This difference in behavior of a-azido-arenes may be accounted for by considering Scheme 2. 

The opinion has been expressed [319] that Ni(acac)2-2o-phda is not an intermediate but merely a competing product of reaction in the macrocyclisation process. However, it should be recalled that during template interactions of ]S-diketones with ethane-1,2-diamine, formation of such adducts is one of the main conditions of macrocycle assemblage [277, 260, 283]. It is not excluded that solid-state template macrocyclisation process can take place, as in the case of Cu(3-N02-acac)2-2en [283]. In this connection it should be noted that Ni(acac)2-2H20 reacts with molten o-phda to give [Ni(L263)] [308]. 

The most noteworthy reaction of azo-compounds is their behaviour on reduction. Prolonged reduction first saturates the azo group, giving the hydrazo derivative (C NH-NH C), and then breaks the NH NH linkage, with the formation of two primary amine molecules. If method (1) has been employed to prepare the azo-compound, these two primary amines will therefore be respectively (a) the original amine from which the diazonium salt was prepared, and (6) the amino derivative of the amine or phenol with which the diazonium salt was coupled. For example, amino-azobenzene on complete reduction gives one equivalent of aniline, and one of p-phenylene diamine, NHaCeH NH benzene-azo-2-naphthoI similarly gives one equivalent of aniline and one of... 

Formation of a Quinoxaline. Heat together for 5 minutes under reflux 0 2 g. of phenanthraquinone dissolved in i ml. of glacial acetic acid and 0-2 g. of O -phenylene diamine also dissolved in i ml, of glacial acetic acid. The yellow substituted quinoxaline (p. 305) separates rapidly. Cool, filter and recrystallise from benzene m.p. 225 . 

As with polyesters, the amidation reaction of acid chlorides may be carried out in solution because of the enhanced reactivity of acid chlorides compared with carboxylic acids. A technique known as interfacial polymerization has been employed for the formation of polyamides and other step-growth polymers, including polyesters, polyurethanes, and polycarbonates. In this method the polymerization is carried out at the interface between two immiscible solutions, one of which contains one of the dissolved reactants, while the second monomer is dissolved in the other. Figure 5.7 shows a polyamide film forming at the interface between an aqueous solution of a diamine layered on a solution of a diacid chloride in an organic solvent. In this form interfacial polymerization is part of the standard repertoire of chemical demonstrations. It is sometimes called the nylon rope trick because of the filament of nylon produced by withdrawing the collapsed film. 

Salt Formation. Salt-forming reactions of adipic acid are those typical of carboxylic acids. Alkali metal salts and ammonium salts are water soluble alkaline earth metal salts have limited solubiUty (see Table 5). Salt formation with amines and diamines is discussed in the next section. 

To produce a spandex fiber by reaction spinning, a 1000—3500 molecular weight polyester or polyether glycol reacts with a diisocyanate at a molar ratio of about 1 2. The viscosity of this isocyanate-terrninated prepolymer may be adjusted by adding small amounts of an inert solvent, and then extmded into a coagulating bath that contains a diamine so that filament and polymer formation occur simultaneously. Reactions are completed as the filaments are cured and solvent evaporated on a belt dryer. After appHcation of a finish, the fibers are wound on tubes or bobbins and rewound if necessary to reduce interfiber cohesion. 

Formic acid forms esters with primary, secondary, and tertiary alcohols. The high acidity of formic acid makes use of the usual mineral acid catalysts unnecessary in simple esterifications (17). Formic acid reacts with most amines to form formylamino compounds. With certain diamines imida2ole formation occurs, a reaction that has synthetic utiHty (18) ... 

Pigment Red 144 [5280-784] 20735 disa2o condensation coupling of dia2oti2ed 2,5-dichloroaniline with 3-hydroxy-2-napthoic acid, foUowed by acid chloride formation and reaction with 2-chloro-/)-phen5iene- diamine... 

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). 

Phosphoric acid [7664-38-2] and its derivatives are effective catalysts for this reaction (60). Reverse alcoholysis and acidolysis can, in principle, also be used to produce polyamides, and the conversion of esters to polyamides through their reaction within diamines, reverse alcoholysis, has been demonstrated (61). In the case of reverse acidolysis, the acid by-product is usually less volatile than the diamine starting material. Thus, this route to the formation of polyamide is not likely to yield a high molecular weight polymer. 

Its manufacture begins with the formation of dodecanedioic acid produced from the trimeri2ation of butadiene in a process identical to that used in the manufacture of nylon-6,12. The other starting material, 1,12-dodecanediamine, is prepared in a two-step process that first converts the dodecanedioic acid to a diamide, and then continues to dehydrate the diamide to the dinitrile. In the second step, the dinitrile is then hydrogenated to the diamine with hydrogen in the presence of a suitable catalyst. 

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. 

Cycloahphatics capable of tertiary carbocation formation are candidates for nucleophilic addition of nitriles. HCN in strong sulfuric acid transforms 1-methyl-1-cyclohexanol to 1-methyl-1-cyclohexylamine through the formamide (47). The terpenes pinene (14) [2437-95-8] and limonene [5989-27-5] (15) each undergo a double addition of HCN to provide, after hydrolysis, the cycloahphatic diamine 1,8-menthanediamine (16) (48). 

V-Phenylsuccinimide [83-25-0] (succanil) is obtained in essentially quantitative yield by heating equivalent amounts of succinic acid and aniline at 140—150°C (25). The reaction of a primary aromatic amine with phosgene leads to formation of an arylcarbamoyl chloride, that when heated loses hydrogen chloride to form an isocyanate. Commercially important isocyanates are obtained from aromatic primary diamines. 

Almost all IDA derived chain extenders are made through ortho-alkylation. Diethyltoluenediamine (DE I DA) (C H gN2) (53), with a market of about 33,000 t, is the most common. Many uses for /-B I DA have been cited (1,12). Both DE I DA and /-B I DA are especially useful in RIM appHcations (49,53—55). Di(methylthio)-TDA, made by dithioalkylation of TDA, is used in cast urethanes and with other TDI prepolymers (56). Styrenic alkylation products of TDA are said to be useful, eg, as in the formation of novel polyurethane—polyurea polymers (57,58). Progress in understanding aromatic diamine stmcture—activity relationships for polyurethane chain extenders should allow progress in developing new materials (59). Chlorinated IDA is used in polyurethane—polyurea polymers of low hysteresis (48) and in reinforced polyurethane tires (60). The chloro-TDA is made by hydrolysis of chloro-TDI, derived from TDA (61). 

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