Ammonia hexamethylenetetramine from

The early addition of Dimedon is reported234 to depress the formation of hexamethylenetetramine from formaldehyde in the presence of ammonia. O Dea282 found that the activated methylene center, sometimes formed in periodate oxidations of carbohydrates, reacts appreciably with the formaldehyde formed, thus giving low yields of apparent formaldehyde. He was able to depress this side reaction by the use of lowered temperatures and by the addition of benzaldehyde or of p-hydroxybenzaldehyde. The analyses for formaldehyde have often been more successful at a pH of 7.5 than at lower pH values.57, 68 59a 60 264... 

It is reported that the compd is formed by the reaction of acetaldehyde-ammonia ammonia (Ref 1). This reaction yielded a max of 87% gum from which the separation of not more than 3% of Hexaethylidenetetramine was possible. Nitration attempt of the product was not considered practicable. The above reaction is analogous to the hexamethylenetetramine from which RDX is prepd by... 

Fig. 9.24. Mechanism for the formation of hexamethylenetetramine from ammonia and formalin.

The details of the process shown in this footnote are not known. However, it is possible that partial hydrolysis of the adamantane (tricyclo[3.3.1.E ]decane, Chapter 1) analogue hexamethylenetetramine (l,2,5,8-tetraazatricyclo[3.3.1.1 - ]decane) to formaldehyde (methanal, CH2O) and ammonia (NH3), from which it was formed by a condensation reaetion (see Chapter 10), provides an oxidizing agent (methanal). 

Tnsubstituted trimethylenetriamine, which may be regarded as the pai-ent compound of this series of products, is apparently an intermediate in the formation of hexamethylenetetramine from formaldehyde and ammonia (page 278). 

Hexamine, more formally known as Hexamethylenetetramine, is easily and conveniently produced from Formaldehyde and Ammonia solutions. Formaldehyde may be easily produced by depolym-erizing, with heat, Paraformaldehyde (the only ingredient in OTC MildewCide). Hexamine is then reacted with Hydrochloric Acid and heated to yield Methylamine HCI in near quantitative yield. 

Hexamethylenetetramine. Hexa, a complex molecule with an adamantane-type stmcture, is prepared from formaldehyde and ammonia, and can be considered a latent source of formaldehyde. When used either as a catalyst or a curative, hexa contributes formaldehyde-residue-type units as well as benzylamines. Hexa [100-97-0] is an infusible powder that decomposes and sublimes above 275°C. It is highly soluble in water, up to ca 45 wt % with a small negative temperature solubiUty coefficient. The aqueous solutions are mildly alkaline at pH 8—8.5 and reasonably stable to reverse hydrolysis. 

Ammonia is used in the fibers and plastic industry as the source of nitrogen for the production of caprolactam, the monomer for nylon 6. Oxidation of propylene with ammonia gives acrylonitrile (qv), used for the manufacture of acryHc fibers, resins, and elastomers. Hexamethylenetetramine (HMTA), produced from ammonia and formaldehyde, is used in the manufacture of phenoHc thermosetting resins (see Phenolic resins). Toluene 2,4-cHisocyanate (TDI), employed in the production of polyurethane foam, indirectly consumes ammonia because nitric acid is a raw material in the TDI manufacturing process (see Amines Isocyanates). Urea, which is produced from ammonia, is used in the manufacture of urea—formaldehyde synthetic resins (see Amino resins). Melamine is produced by polymerization of dicyanodiamine and high pressure, high temperature pyrolysis of urea, both in the presence of ammonia (see Cyanamides). 

Glycine ethyl ester hydrochloride has been prepared by the action of absolute alcohol and hydrogen chloride on glycine from glycyl chloride and alcohol by the action of ammonia or hexamethylenetetramine on chloroacetic acid, and subsequent hydrolysis with alcoholic hydrochloric acid and by the action of hydrogen chloride and alcohol on methyleneamino-acetonitrile. ... 

It is made by the nitration of hexamine (hexamethylenetetramine), itself prepared from formaldehyde and ammonia. Hexamine was originally nitrated with a large excess of concentrated nitric acid at temperatures below 30°C and the product recovered by adding the reaction liquor to an excess of chilled water. Later the yield was improved by adding ammonium nitrate to the reaction as this reacts with the liberated formaldehyde. A much-used process converts the hexamine first to its dinitrate, which is then reacted with ammonium nitrate, nitric acid and acetic anhydride (the last reagent being re-formed from the product by use... 

Only 1,3,5,7-tetraazaadamantane is known. It is also called hexamethylenetetramine (93) (HMT), hexamine, aminoform, ammoform, cyctamin, cystogen, formin, uritone, urotropin, and methenamine. It is listed by the last name in the Merck Index. It is prepared from formaldehyde and ammonia. The chemistry of this well-known compound is not discussed in this review. 

Paquin in 1948 found that a strongly exothermic reaction occurred when 40% formaldehyde was added to a solution of sulfamide in 25% aqueous ammonia. At once beautiful crystals precipitated they were recrystallized from 96% alcohol to give a compound, C5H10N4SO2, mp 224-225 "C, in 88% yield.245 From the similar character to hexamethylenetetramine, he named this product pentamethylenetetramine sulfone it is 225. One year later, in 1949, Hecht and Henecka at Bayer research laboratory reported that a condensation product from one mole of sulfamide in strong mineral acid and two moles of formaldehyde showed very strong toxicity and was five times more toxic than strychnine. They called this product (226) tetra-methylenedisulfotetramine. 246... 

Hydrogen peroxide is also complexed with hexamethylenetetramine, industrially prepared from formaldehyde and ammonia, which advantageously replaces DABCO. This... 

Methylamine occurs in herring brine 2 in crude methyl alcohol from wood distillation,3 and in the products obtained by the dry distillation of beet molasses residues.4 It has been prepared synthetically by the action of alkali on methyl cyanate or iso-cyanurate 5 by the action of ammonia on methyl iodide,6 methyl chloride,7 methyl nitrate,8 or dimethyl sulfate 9 by the action of methyl alcohol on ammonium chloride,10 on the addition compound between zinc chloride and ammonia,11 or on phos-pham 12 by the action of bromine and alkali on acetamide 13 by the action of sodamide on methyl iodide 14 by the reduction of chloropicrin,15 of hydrocyanic or of ferrocyanic acid,16 of hexamethylenetetramine,17 of nitromethane,18 or of methyl nitrite 19 by the action of formaldehyde on ammonium chloride.20... 

The condensation products of aldehydes with ammonia or amido-eoinpounds are easily reduced to amines in sulphuric-acid solution at lead cathodes. Thus hexamethylenetetramine yields methylamine (Knudson 2) ethylideneimine, ethylamine the base from acetaldehyde and ethylamine, diethylamine. Aromatic aldehydes behave similarly. The Farbwerke vorm. Meister,... 

It also can be produced directly from natural gas, methane, and other aliphatic hydrocarbons, but this process yields mixtures of various oxygenated materials. Because both gaseous and liquid formaldehyde readily polymerize at room temperature, formaldehyde is not available in pure form. It is sold instead as a 37 percent solution in water, or in the polymeric form as paraformaldehyde [HO(CH20)nH], where n is between 8 and 50, or as trioxane (CH20)3. The greatest end use for formaldehyde is in the field of synthetic resins, either as a homopolymer or as a copolymer with phenol, urea, or melamine. It also is reacted with acetaldehyde to produce pentaerythritol [C(CH2OH)4], which finds use in polyester resins. Two smaller-volume uses are in urea-formaldehyde fertilizers and in hexamethylenetetramine, the latter being formed by condensation with ammonia. 

Acid Amides can be produced by acylating ammonia with esters, acid anhydrides, or the acids themselves (above 100 °C) an important product is formamide from methyl formate. Alternatively acid amides can be synthesized by reacting acid halides with ammonia. Catalytic hydrogenation converts the acid amides to primary amines. Ammonia and aldehydes or ketones are the basis for different stable products. With formaldehyde hexamethylenetetramine (urotropine) is obtained with acetaldehyde, ammono acetaldehyde with benzaldehyde, hydrobenzamide with ethylene and propylene oxides, aqueous ammonia reacts to form ethanol- or propanolamine. 

Now according to the present Invention it has been found that hexamethylenetetramine, the well know n condensation product obtained from formaldehyde and ammonia, yields, when suitably treated with concentrated nitric acid, an extraordinarily powerful explosive compound, which combines in itself in an absolutely ideal manner the favourable properties of the ethereal salts of nitric acid and the aromatic nitro compounds. 

Hence, the initial major product is a mono-substituted phenol [Eq. (1)]. Because the reaction is done under aqueous acidic conditions, the products shown in Eq. (1) are not isolated. Instead, a methylene bridge is formed between the phenyl rings [Eq. (2)]. In both Eqs. (1) and (2) the mechanism is an electrophilic aromatic substitution. Heating the system so as to promote removal of water and polymerization results in thermoplastic material known as novolac (1). This thermoplastic resin can be mixed with hexamethylenetetramine (formed from ammonia and formaldehyde) and stored until cure. Heating this system produces an excess of formaldehyde and ammonia. A cross-linked polymer results from the cure. The linkages are mostly methylene and amino groups. 

Laboratory studies have provided evidence that photochemical and photocatalytic (Section 6.8) steps might play an important role in the formation of amino acids or various heterocyclic compounds from very simple molecules. For example, UVC irradiation of acetonitrile ammonia water mixture produces hexamethylenetetramine, a potential precursor of amino acids, via two-step photoinitiated fragmentation of acetamide (formed by acetonitrile hydrolysis) to give carbon oxide, which undergoes further photochemical and dark reactions (Scheme 6.184).1183... 

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