Diamines esters

The construction of a diazaadamantane skeleton under microwave conditions has been explored by Ivachtchenko and colleagues (Scheme 2.273) [462], Cleavage of semi-natural tetrahydro-(-) -cytisine in acidic methanol provided the corresponding free diamine ester, which was used directly in the next step without purification. Thus, l,T-carbonyldiimidazole (CDI) in a water/methanol mixture was added at... 

Synthesis of PEAs by polycondensation has usually been performed by reacting diamide-diol, diester-diamine, ester-diamine, or diamide-diester monomers with dicar-boxylic acid derivatives or diols (Figure 8.1). In addition, a,o)-amino alcohols can be also reacted with acid anhydrides or dicarboxylic acid derivatives. 

Kinetic and mechanistic studiesoftheimidizationreactionhave been made and the effects of amine activators, catalysts, and palladium " have all been studied. Imide plastics have also been produced by the reaction of diamine-esters of poly(dicarboxylic acid) on filler surfaces in a quasi reaction-injection moulding process. ... 

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). 

Amidation. Heating of the diammonium salt or reaction of the dimethyl ester with concentrated ammonium hydroxide gives adipamide [628-94-4] mp 228°C, which is relatively insoluble in cold water. Substituted amides are readily formed when amines are used. The most industrially significant reaction of adipic acid is its reaction with diamines, specifically 1,6-hexanediamine. A water-soluble polymeric salt is formed initially upon mixing solutions of the two materials then hea ting with removal of water produces the polyamide, nylon-6,6. This reaction has been studied extensively, and the hterature contains hundreds of references to it and to polyamide product properties (31). 

Reduction. Hydrogenation of dimethyl adipate over Raney-promoted copper chromite at 200°C and 10 MPa produces 1,6-hexanediol [629-11-8], an important chemical intermediate (32). Promoted cobalt catalysts (33) and nickel catalysts (34) are examples of other patented processes for this reaction. An eadier process, which is no longer in use, for the manufacture of the 1,6-hexanediamine from adipic acid involved hydrogenation of the acid (as its ester) to the diol, followed by ammonolysis to the diamine (35). 

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) ... 

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. 

Hydrazine [302-01-2] (diamide), N2H4, a colorless liquid having an ammoniacal odor, is the simplest diamine and unique in its class because of the N—N bond. It was first prepared in 1887 by Curtius as the sulfate salt from diazoacetic ester. Thiele (1893) suggested that the oxidation of ammonia (qv) with hypochlorite should yield hydrazine and in 1906 Raschig demonstrated this process, variations of which constitute the chief commercial methods of manufacture in the 1990s. 

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. 

Bisamides. Methylenebisamides are prepared by the reaction of the primary fatty amide and formaldehyde in the presence of an acid catalyst. AijAT-Methylenebisoleamide has been made via this route without the use of refluxing solvent (55). Polymethylenebisamides can be made from fatty acid, esters, or acid haUdes with diamines while producing water, alcohol, or mineral acid by-products. Eatty acids and diamines, typically ethylenediamine, have been condensed in the presence of NaBH and NaH2P02 to yield bisamides (56). When stearic acid, ethylenediamine, and methyl acetate react for 6 h at... 

Bis(chloroformic esters) condense with diamines to give polyurethanes (60) (see Urethane polymers). 

Castor esters have been found to be nonirritating and noncomedogenic to the skin. Cetyl ricinoleate was found to be an effective noncomedogenic moisturizer (118). Castor-based quaternaries prepared by reaction of a castor fatty acid and a tertiary diamine are used for hair care. The ricinoleic quaternium is incorporated into clear shampoo formulations for foam enhancement and conditioning (119,120). 

PolybenZimidaZoles. The polyben2imida2oles (PBIs) are generally produced by the high temperature, melt polycondensation reaction of aromatic bis-ortho-diamines and aromatic dicarboxylates (acids, esters, or amides) in a reaction such as that shown in equation 11 to form ben2imida2ole [51-17-2] as the repeating unit. 

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. 

X-ray, 4, 160 (79AX(B)2228> lH-Pyrrole-2,4-diamine, 1-t-butyl-JV, JV -dimethyl-3-phenyl-JV -phenylsulfonyl-X-ray, 4, 160 (78BSB893) lH-Pyrrole-3-methanol, 4-acetyl-X-ray, 4, 160 (78AX(B)1248> lH-Pyrrole-3-methanol, 4-acetyl-, hydrate X-ray, 4, 160 (78AX(B)1248> lH-Pyrrole-3-propanoic acid, ester C NMR, 4, 172 (74JCS(P2)1004>... 

PhCH20COCl, Na2C03, H20,0°, 30 min, 72% yield. Alpha-omega diamines can be protected somewhat selectively with this reagent at a pH between 3.5 and 4.5, but the selectivity decreases as the chain length increases [H2N(CH2) NH2, n = 2, 71% mono n = l, 29% mono]. Hindered amino acids are protected in DMSO (DMAP, TEA, heat, 47-82% yield). These conditions also convert a carboxylic acid to the benzyl ester. ... 

Finally, the quinoline ring can be methylated at the 3 position with retention of biologic activity. The starting quinoline is prepared by the same scheme as that used for the desmethyl compound by substituting the methylated oxosuccinate ester, S6, in the sequence. The initial quinoline carboxylate (87) is taken on to the dichloro compound (88) by the standard reactions. Condensation with the ubiquitous diamine (76) affords sontoquine (89)... 

The main use of acrolein is to produce acrylic acid and its esters. Acrolein is also an intermediate in the synthesis of pharmaceuticals and herhicides. It may also he used to produce glycerol hy reaction with isopropanol (discussed later in this chapter). 2-Hexanedial, which could he a precursor for adipic acid and hexamethylene-diamine, may he prepared from acrolein Tail to tail dimenization of acrolein using ruthenium catalyst produces trans-2-hexanedial. The trimer, trans-6-hydroxy-5-formyl-2,7-octadienal is coproduced. Acrolein, may also he a precursor for 1,3-propanediol. Hydrolysis of acrolein produces 3-hydroxypropionalde-hyde which could he hydrogenated to 1,3-propanediol. ... 

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