Hexamethylenetetramine, amine

In a 500 ml. flask, fitted with a reflux condenser, place 53 g. of 1-chloro-methylnaphthalene (Section IV.23), 84 g, of hexamethylenetetramine and 250 ml. of 1 1 acetic acid [CAUTION 1-Chloromethylnaphtha-lene and, to a lesser degree, a-naphthaldehyde have lachrymatory and vesicant properties adequate precautions should therefore be taken to avoid contact with these substances.] Heat the mixture under reflux for 2 hours it becomes homogeneous after about 15 minutes and then an oil commences to separate. Add 100 ml. of concentrated hydrochloric acid and reflux for a further 15 minutes this will hydrolyse any SchifiF s bases which may be formed from amine and aldehyde present and will also convert any amines into the ether-insoluble hydrochlorides. Cool, and extract the mixture with 150 ml. of ether. Wash the ether layer with three 50 ml. portions of water, then cautiously with 50 ml. of 10 per cent, sodium carbonate solution, followed by 50 ml. of water. Dry the ethereal solution with anhydrous magnesium sulphate, remove the ether by distillation on a steam bath, and distil the residue under reduced pressure. Collect the a-naphthaldehyde at 160-162718 mm. the yield is 38 g. 

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). 

Although in the dry state carbon tetrachloride may be stored indefinitely in contact with some metal surfaces, its decomposition upon contact with water or on heating in air makes it desirable, if not always necessary, to add a smaH quantity of stabHizer to the commercial product. A number of compounds have been claimed to be effective stabHizers for carbon tetrachloride, eg, alkyl cyanamides such as diethyl cyanamide (39), 0.34—1% diphenylamine (40), ethyl acetate to protect copper (41), up to 1% ethyl cyanide (42), fatty acid derivatives to protect aluminum (43), hexamethylenetetramine (44), resins and amines (45), thiocarbamide (46), and a ureide, ie, guanidine (47). 

A number of disinfectants apparentiy owe their activity to formaldehyde, although there is argument on whether some of them function by other mechanisms. In this category, the dmg with the longest history is hexamethylenetetramine (hexamine, urotropin) [100-97-0] which is a condensation product of formaldehyde and ammonia that breaks down by acid hydrolysis to produce formaldehyde. Hexamine was first used for urinary tract antisepsis. Other antimicrobials that are adducts of formaldehyde and amines have been made others are based on methylolate derivations of nitroalkanes. The apphcations of these compounds are widespread, including inactivation of bacterial endotoxin preservation of cosmetics, metal working fluids, and latex paint and use in spin finishes, textile impregnation, and secondary oil recovery (117). 

The present procedure was developed from those of Wallach and Freylon, based upon the general method discovered by Leuckart. a-Phenylethylamine also can be prepared satisfactorily by the reduction of acetophenone oxime with sodium and absolute alcohol or sodium amalgam, but the reagents are more expensive and the processes less convenient. The amine has been obtained by reducing acetophenone oxime electro-lytically, by reducing acetophenone phenylhydrazone with sodium amalgam and acetic acid, from a-phenylethyl bromide and hexamethylenetetramine, and by the action of methyl-magnesium iodide upon hydrobenzamide, as well as by other methods of no preparative value. 

Tannins can also be hardened by addition of hexamethylenetetramine (hex-amine) [146,147], whereby these boards show very low formaldehyde emission [16-18,148-151]. 

The oxime of bromoacetylfurazan 123 was converted into the amine 125 by treatment with hexamethylenetetramine and subsequent acidic hydrolysis. Oxa-diazine derivative 126 was made from the amine and formaldehyde in 57% yield (Scheme 73) (97ROC1760, 97ZOR1844). 

Primary amines through reaction of alkyl halides with hexamethylenetetramine... 

Reaction of alkyl halides 1 with hexamethylenetetramine 2 (trivial name urotropine) followed by a hydrolysis step, leads to formation of primary amines 3 free of higher substituted amines. This method is called the Delepine reaction, a comparable method is the Gabriel synthesis. 

Primary amines can be prepared from alkyl halides by the use of hexamethylenetetramine followed by cleavage of the resulting salt with ethanolic HCl. The method, called the Delepine reaction, is most successful for active halides such as allylic and benzylic halides and a-halo ketones, and for primary... 

The Delepine reaction Involves nucleophilic displacement of active halides by hexamethylenetetramine, followed by hydrolysis of Intermediate quaternary ammonium salt to release the amine. 

Normally the reaction Is useful for the conversion of alkyl halides to primary amines without concomitant formation of secondary amines.29 Treatment of polymer 17 with hexamethylenetetramine in a mixture of ethanol/THF afforded an insoluble resin. Using diazabicyclooctane (DABCO), we demonstrated that the reaction could be limited to attack by a single nitrogen in a multifunctional amine, so we did not anticipate crosslinking via bis-quat salt formation. Hydrolysis of 2 with anhydrous HC1 in ethanol generated free amino groups as evidenced by a positive ninhydrin test, but quantitative hydrolysis could not be achieved and the product remained insoluble. One would have expected a simple bis-quat to hydrolyse and open the crosslinked structure. 

Silver(I) complexes with polyamines also form molecular aggregates, thus hexamethylenetetramine yields 2D and 3D coordination networks,613 polymeric chains are obtained with diethylene-triamine, tris(2-aminoethyl)amine, or A,A -bis(aminoethyl)propane-l,3-diamine,426 and 2D networks are formed with thiocyanate and bridging polyamines.61... 

Delepine reaction org chem Slow ammonolysis of alkyl halides in acid to primary amines in the presence of hexamethylenetetramine. del-3,pTn re,ak-sh3n deliquescence phys chem The absorption of atmospheric water vapor by a crystalline solid until the crystal eventually dissolves into a saturated solution. del-3 kwes-3ns ... 

The reaction between alkyl halides and hexamethylenetetramine, followed by cleavage of the resulting salt with ethanolic HCl to yield primary amines. 

Conversion of Alkyl Halides to Primary Amines with Hexamethylenetetramine Amino-de-halogenation (overall transformation)... 

Another way to oxidize primary alkyl halides to aldehydes is by the use of hexamethylenetetramine followed by water. However, this reaction, called the Sommelet reaction. is limited to benzylic halides. The reaction is seldom useful when the R in RCH2CI is alkyl. The first part of the reaction is conversion to the amine ArCH2NH2 (0-44), which can be isolated. Reaction of the amine with excess hexamethylenetetramine gives the aldehyde. It is this last step that is the actual Sommelet reaction, though the entire process can be conducted without isolation of intermediates. Once the amine is formed, it is converted to an imine (ArCH2N=CH2) with formaldehyde liberated from the reagent. The key step then follows transfer of hydrogen from another mole of the arylamine to the imine ... 

Alkylation of ammonia or amines 0-44 Reaction between alkyl halides and hexamethylenetetramine (Dele-pine)... 

Amine Peroxides as Explosives. Some amines may yield expl peroxides. For instance, hexamethylenetetramine when treated with hydrogen peroxide in the presence of an organic add(citric) which combines with the liberated Nris, forms hexamethylenetriperoxidediamineiqv) (Ref IX Schif f s bases, ammoniacal aldehydes or their... 

Formaldehyde reacts with amines to yield the 1,3,5-trisubstituted hexahydro-1,3,5-triazines and with nitriles to form the acyl derivatives (Scheme 90) (59HC(13)1, p. 486, B-61MI22000, p. 658). Hexamethylenetetramine (70) is prepared by heating an ammoniacal solution of formaldehyde (B-61MI22000, p. 688). 

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