Hexamethylenetetramine HMT

Another reagent, hexamethylenetetramine (HMT) has also been used in place of urea for the homogeneous preparation of LDHs. HMT hydrolyzes at high temperature in aqueous solution with the release of ammonia, which makes the solution alkahne, and formaldehyde, which would not be expected to be incorporated into the LDH. Using HMT, well-crystalhzed 1-5 p.m -sized particles of chloride-intercalated LDHs were prepared in a pressure... 

Treatment of duocarmycin segment A derivative 99 with hexamethylenetetramine (HMT) in TEA gives the novel ring structure 139 (Equation 38) <2000BMC1195>. 

We have investigated a variety of clusters with ethers and amines as the Rydberg donor systems and polar solvents as the acceptors. The donors we have studied include dioxane (C4H802), azabicyclooctane (ABCO), diazabicyclooctane (DABCO), hexamethylenetetramine (HMT), and others (Moreno et al. 1992 Shang and Bernstein 1994 Shang et al. 1993a,b,c, 1994a,b,c). The acceptors include ethers, amines, and aromatics. 

Andrew, D.J., Lindsay, C.D. (1998a). Protection of human upper respiratory tract cell lines against sulphur mustard toxicity hy hexamethylenetetramine (HMT). Hum. Exp. Toxicol. 17 373-9. 

Al-sol can be prepared using various aluminum precursors, such as pseudo-boehmite, A10(0H) xH20, and aluminum alkoxide [48-50,55,60]. Xu et al. [55] described several possibilities. Additives, e.g., urea, or organic amines, e.g., hexamethylenetetramine (HMT), can be added to the sol in order to improve the quality of alumina obtained. The decomposition of these additives in heat treatment (calcination) may lead to a better porosity of the alumina. The reaction for urea decornposition is as follows ... 

Although several workers have studied the reaction of hexamethylenetetramine (hmt l,3,5,7-tetraazatricyclo[3.3.1.13.7]decane) with phosgene, the product has never been fully characterized, despite its alleged importance as a prophylactic agent in phosgene poisoning (Section 2.6). 

Example 5-5 Hexamethylenetetramine (HMT) is to be produced in a semibatch reactor by adding an aqueous ammonia solution (25 wt % NH3) at the rate of 2 gpm to an initial charge of 238 gal (at 25°C) of formalin solution containing 42% by weight formaldehyde. The original temperature of the formalin solution is raised to 50°C in order to start the reaction. The temperature of the NH4.OH solution is 25°C. The heat of reaction in the liquid phase may be, assumed independent of temperature and concentration and taken as —960 Btu/lbbf HMT. If the reactor can be operated at a temperature of 100°C, the rate of reaction is very fast in comparison with the rate of heat transfer with the surroundings. Temperatures higher than 100°C are not desirable because of vaporization and increase in pressure. 

Among the most interesting organic molecules recently discovered in comets are polyoxymethylene [(-CH2-0-)n], also known as POM, a polymer of formaldehyde (CH20) and hexamethylenetetramine (HMT C6H12N4). These two compounds are thought to he the source of simpler compounds, such as the organic species listed in... 

Hexamethylenetetramine, HMT, HMTA, hexam-ine. Urinary antiseptic releases formaldehyde in urine and this kills bacteria. Used with sodium phenate and NaOH as an absorbant of poisonous gases. Tried unsuccessfully as an antidote to phosgene. 

S879, Methenamine. 1,3,S,7-Tetraazairicycto[3.3.1.1,7J-dccane hexamethylenetetramine HMT HMTA hexamme 1.3,5,7-letraazaadamantane hexamethylenamine Amino -form Ammoform Cystamin Cystogen Foraiin Uritone Urotropin. C4H,2N4 mol wt 140.19. C 51.40%, H 8.63%. N 39.97%. From formaldehyde and ammonia Meissner,... 

While many of these new species sublime when the irradiated ice is warmed from 200K to room temperature under vacuum, a thick oily residue of nonvolatile material remains. Among many other things, this residue is rich in the cage molecule hexamethylenetetramine (HMT, C6H12N4) 38). This contrasts with the organic residues produced by irradiating mixed molecular ices which do not contain methanol (e.g. refs. 14, 38, 39) and those produced in thermally promoted polymerization-type reactions in non-irradiated realistic ice mixtures... 

Useful in the plants where phosgene was manufactured was the discovery that hexamethylenetetramine (HMT) was an effective prophylactic against phosgene poisoning. The compound rapidly combined with phos-... 

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