Methylenediamines

The amine, under the name N,N,N, N -tetramethyl-methylenediamine, may be purchased from Ames Laboratories, South Norwalk, Connecticut. The checkers prepared it by the following procedure. A solution of 60.7 g. (0.75 mole) of 37% aqueous formaldehyde solution is placed in an 800-ml. beaker equipped with a mechanical stirrer and thermometer, and cooled in an ice bath. Two hundred seventy-one grams (1.50 moles) of a 25% aqueous solution of dimethylamine is added to this solution at a rate such that the reaction temperature is kept below 15°. The solution is stirred for 30 minutes after the addition is complete, and potassium hydroxide pellets (approximately 150 g.) are added in portions until the reaction mixture separates into two layers. The upper layer is separated, dried over potassium hydroxide pellets overnight, and distilled to give 59 -64 g. (77-83%) of bis(dimcthylamin())mclliane, b.p. 83 84°. ... 

Further reduction of 3,4-dihydroquinazoline to l,2,3,Jt-tetTahydro-quinazoline is more difficult, but it can be accomplished with sodium amalgam or by catalytic reduction with palladium-charcoal. 1,2,3,4-Tetrahydroquinazolines have also been prepared by condensing o-aminobenzylamines with various aldehydes and with formaldehyde or methylenediamines (see 3b). 

Butadiene is by far the most important monomer for synthetic rubber production. It can be polymerized to polybutadiene or copolymerized with styrene to styrene-butadiene rubber (SBR). Butadiene is an important intermediate for the synthesis of many chemicals such as hexa-methylenediamine and adipic acid. Both are monomers for producing nylon. Chloroprene is another butadiene derivative for the synthesis of neoprene rubber. 

Pimelic Acid (Heptanedioic Acid or 1,5-Pentane-dicarboxytlc Acid). HOOC.(CH2)s.COOH mw 160.17 white prisms mp 106° bp 272° at 100mm (subl), and 212° at 10mm d 1.329 g/cc at 15°. Sol in w, ethanol, eth and hot benz. Prepn is by oxidn of cycloheptanone, capric acid or oleic acid treatment of salicylic acid with Na in amyl ale, or by decarboxylating 1,1,5,5-pentanetetracarboxylic acid with heat Pimelic acid has been combined with cis and trans-, 4-cyclohexanediol to give polyesters, and with m-xylene-ce,ol -diamine or poly-methylenediamines to form polyamides. With diperoxides, the acid forms resins. It is also used as the parent compd to form the expls presented below... 

Hydrogenation, of gallic add with rhodium-alumina catalyst, 43, 62 of resorcinol to dihydroresorcinol, 41,56 Hydrogen peroxide, and formic acid, with indene, 41, 53 in oxidation of benzoic add to peroxy-benzoic add, 43, 93 in oxidation of ieri-butyl alcohol to a,a/r, a -tetramcthyltetra-methylene glycol, 40, 90 in oxidation of teri-butylamine to a,<, a, a -tetramethyltetra-methylenediamine, 40, 92 in oxidation of Crystal Violet, 41, 2, 3—4... 

Zinc dithiocarbamates have been used for many years as antioxidants/antiabrasives in motor oils and as vulcanization accelerators in rubber. The crystal structure of bis[A, A-di- -propyldithio-carbamato]zinc shows identical coordination of the two zinc atoms by five sulfur donors in a trigonal-bipyramidal environment with a zinc-zinc distance of 3.786 A.5 5 The electrochemistry of a range of dialkylthiocarbamate zinc complexes was studied at platinum and mercury electrodes. An exchange reaction was observed with mercury of the electrode.556 Different structural types have been identified by variation of the nitrogen donor in the pyridine and N,N,N, N -tetra-methylenediamine adducts of bis[7V,7V-di- .vo-propyldithiocarbamato]zinc. The pyridine shows a 1 1 complex and the TMEDA gives an unusual bridging coordination mode.557 The anionic complexes of zinc tris( V, V-dialkyldithiocarbamates) can be synthesized and have been spectroscopically characterized.558... 

Reactant 7.123 can be prepared by reacting acrylonitrile with s-trioxane (Scheme 7.74) using an acid catalyst in carbon tetrachloride as solvent [147]. Two commercially available bifunctional reactants, N,N -bis(acryloyl)methylenediamine (7.133) and its water-soluble bis-quaternary precursor (7.134), have been evaluated to achieve dyeings of similar quality at lower cost. The precursor is readily converted to the active reactant at about pH 8 during... 

Torsional parameters and VdW parameters for internal hydrogen bonds in the N—C—N moiety were obtained by fitting the ab initio rotational profiles of methylenediamine (MDA, 15) and /V-methylmelliylenediamine (NMMDA, 16). A comparison of relative conformational energies between ab initio and MM2 results for 15 and 16 is provided in Table 6. Bond length correction terms for inner and outer C—N bonds (K, K2 and... 

TABLE 6. Relative energies (kcal mol-1) of all possible conformers of methylenediamine (MDA, 15) and N-methylmethylenediamine (NMMDA, 16) as calculated ab initio (HF/3-21G//HF/3-21G) and with the reparameterized force field (MM2-87 version)". Reproduced from Ref. 22b by permission of Elsevier Science Ltd... 

Let us start with aliphatic species and sequentially move the amino groups apart. We are seemingly thwarted immediately. There is no enthalpy of formation reported for methylenediamine (diaminomethane) CH2(NH2)2 (21), a species we recognize as the simplest polyaminoalkane. As such the exothermicity of reaction 22... 

The direct A -nitration of the amino groups of the hexahydrotriazine (23) is only possible due to the inherent low basicity of the methylenediamine functionality. The methylenediamine unit is present in many cyclic and bicyclic polyamines and these are potential precursors to energetic polynitramines. Unfortunately, this route to polynitramines is rarely possible because such polyamines are usually intrinsically unstable and will readily equilibrate to a lower energy, less strained system. For the same reason, polyamines containing the methylenediamine functionality are difficult to prepare and isolate, often rapidly decomposing in both aqueous and acidic solution. A far more common route involves the preparation of iV-protected versions of the polyamine followed by nitrolysis (Section 5.6). Even so, examples of heterocyclic methylenediamine iV-nitration exist. 

As previously discussed, heterocyclic polyamines containing methylenediamine functionality are usually unstable if unprotected. In contrast, the presence of a urea group stabilizes this functionality and allows the isolation of a number of heterocyclic amines. These are usually synthesized via a condensation reaction and isolated as the hydrochloride salt. The A-nitration of the 2,5,7,9-tetraazabicyclo[4.3.0]nonan-8-one and 2,4,6,8-tetraazabicyclo[3.3.0]octan-3-one ° ring systems has been investigated and serve as valuable examples. 

The scope of nitrolysis is huge, with examples of nitramine formation from the cleavage of tertiary amines, methylenediamines, carbamates, ureas, formamides, acetamides and other amides. The deflnition of nitrolysis must be extended to the nitrative cleavage of other nitrogen bonds because sulfonamides and nitrosamines are also important substrates for these reactions. The nitrative cleavage of silylamines and silylamides is also a form of nitrolysis (Section 5.7). 

The nitrolysis of tertiary amines in the form of fert-butylamines and methylenediamines has been used to synthesize numerous polynitramine-based energetic materials. In these reactions one of the N-C bonds is cleaved to generate a secondary nitramine and an alcohol the latter is usually 0-nitrated or oxidized under the reaction conditions (Equation 5.15). The ease in which nitrolysis occurs is related to the stability of the expelled alkyl cation. Consequently, the fert-butyl group and the iminium cation from methylenediamines are excellent leaving groups. 

Methylenediamines are readily synthesized from the reaction of secondary amines with formaldehyde. Many aliphatic amines are too basic for direct nitration without a chloride catalyst, and even then, nitrosamine formation can be a problem. Their conversion into intermediate methylenediamines before nitration is therefore a useful route to secondary nitramines. The success of these nitrolysis reactions is attributed to the inherent low basicity of the methylene-diamine nitrogens. 

The most important nitrolysis reaction to date is the formation of RDX (3) and HMX (4) from the caged methylenediamine known as hexamine (104). These important military explosives were first mass manufactured by this route towards the end of the Second World War and they are still prepared by this route today. The process uses a mixture of acetic anhydride, ammonium nitrate and nitric acid. The nitrolysis of hexamine is one of the most widely studied reactions in the history of explosives. Many other cyclic and linear polynitramines have been isolated from these reactions and this rich chemistry is discussed in more detail in Section 5.15. 

Chapman studied the nitrolysis of symmetrical methylenediamines. The nitrolysis of N, N, N, M-tetramethylmethylenediamine with nitric acid-acetic anhydride-ammonium nitrate mixtures gives both dimethylnitramine and RDX the latter probably arises from the nitroT ysis of hexamine formed from the reaction of ammonium nitrate and formaldehyde released from the hydrolysis of the methylenediamine. The same reaction with some morpholine-based methylenediamines (105) allows the synthesis of l,3,5-trinitro-l,3,5-triazacycloalkanes (106). 

The nitrolysis of substituted methylenediamines with nitronium salts can lead to a number of products depending on the nature of the substituents within the substrate. Electron-withdrawing or resonance-stabilizing groups favour the expulsion of an immonium ion and the formation of a secondary nitramine in yields between 58 % and 78... 

A solution of dinitrogen pentoxide in methylene chloride-acetonitrile also yields secondary nitramines from symmetrical methylenediamines. When the substiment is aliphatic or heterocyclic the nitrolysis occurs specifically at the aminal methylene and yields of secondary nitramine between 25 % and 54 % are reported. 

The furazan-based heterocycle (12) is iV-nitrated to the corresponding nitramine (13) with nitrogen pentoxide in nitric acid without chloride catalyst because of the inherent low basicity of the methylenediamine functionality." ... 

Equilibrium studies have shown that the first formation constant of the chromium(iii)-ethylenediamine system is < 10, over 10 -fold smaller than the value (10 ) previously reported. [Cr(en)3 (tn) ] (x = 0—3 and tn = tri-methylenediamine) complexes have been prepared and resolved using nitro-(-f )D-camphor. These mixed complexes have the same absolute configuration, A, as the pure [Cr(en)3] and [Cr(tn)3] species. Selective intervention of an optically active counterion in the relaxation processes of excited enantiomeric complexes can lead to partial resolution. This has been achieved for [Cr(phen)3] using D-tartrate. ... 

Dilithiated diamine 2 was synthesized by Karsch by a two-fold metalation of N,N,N, N tetramethylmethylenediamine (TMMDA) (1). The reaction was effected in n-pentane at low temperatures, yielding the poorly soluble Af,Af -bis(fithiomethyl)-Af,Af -dimethyl-methylenediamine (2) (Scheme 1). Due to its low solubility in toluene or THE, the highly pyrophoric compound was characterized by derivatization with several electrophiles, mainly chlorosilanes. Obviously, the addition of coordinating additives, such as TMEDA, DME (dimethoxyethane) or THE, does not enhance the solubility of the dilithium compound. Interestingly, as the author comments, TMEDA is only monolithiated in modest yields by alkyllithium bases. 

N-Ethyl-methylenediamine. See Diaminopro-pane in Vol 5 of Encycl, p D1142... 

Free ligands containing methylenediamine linkages have not been isolated because such ligands decompose when the metal ion is taken out of the complex. 

NjN -Dinifro-NfN -diethyl methylenediamine NfN -Bi (ethyJnrtromine)-methone or 3,5-Din itro-3,5-diozahepfane,... 

The highest yield was obtd by Chute et al (Ref 7. p 231) by interaction of dimethylo nitramide and methylenediamine sulfate conducted.as folLows The dimechylolnitramide was prepd from 2 moLes of CH20 and 1 mole of N03.NH2 as described on p 68 of Ref 4. 

The methylenediamine sulfate was prepd by method of Knudsen (Ref 2) from methylene-diformamide and sulfuric acid using a sulfuric acid ratio of 5 6, while he suggested 3 4 (Ref 7, p 23D... 

Procedure To a cold (at 0°C) nitramide-formaldehyde soln, prepd by mixing 0.10g (0.0016 mole) of dimethylolnitramide and 0,12ml (0,0016 mole) of 37% formaldehyde, was added 0.20g (0.0011 mole) of methylenediamine sulfate dissolved in 7.5ml water. The resulting soln was cooled to 0° and neutralized to pH 7 with satd aq soln of Na carbonate. The wh ppc which appeared at once was filtered after 40 mins, washed with 10ml water, and dried at 50°C. The product weighed 0.085g (yield... 

Other chemicals present in tlie fibres operation or in other operations on sites of the companies in the epidemiological study by Blair et al. (1998) include adiponitrile, hexa-methylenediamine, polyester, polystyrene, vinyl acetate, /, /-diincthylacetamidc, titanium dioxide, propionitrile, methyl methacrylate, zinc chloride, dyes and vinyl bromide (McCammon Zey, 1990 Zey McCammon, 1989 Zey Bloom, 1990). 

Diethyl-methylenediamine and derivs 5 D1239 N,N,-dmitro-N>N,-diethyl-methylenediamine 5 D1239... 

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