F,
XnRelevant articles and documents
All total 31 Articles be found
All total 31 Articles be found-
Bachmann et al.
, p. 2769,2772 (1951)
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Hexaazapolycycles by selective multimethylenations with dichloromethane and base or with hexamethylenetetramine
Kaupp, Gerd,Sailer, Klaus
, p. 47 - 50 (1996)
Multiple methylenations of 2-aminomethylbenzimidazole with dichloromethane and methylamine or ammonia or with hexamethylenetetramine lead to highly selective formations of 6 new single bonds to give only a polycyclic bis-spiro-1,5-diazocine 2 or only a polycyclic spiro-1,3,6-triazonine 4 or only a polycyclic 1,3,6,8-tetrazecine derivative 6. 4 and 6 may be equally well obtained starting with 2-chloromethyl-benzimidazole. All of these selectively formed products are concave cryptands with 6 amino nitrogen atoms. No template metals are used in their syntheses. The reasons for the unusual changes in selectivity are investigated using semi-empirical PM3 calculations and mechanistic considerations. Experimental and spectroscopic details are given. Johann Ambrosius Barth 1996.
N-denitration of nitramines by dihydronicotinamides
Chapman, Robert D.,O'Brien, Richard A.,Kondracki, Paul A.
, p. 9655 - 9664 (1996)
N-NO2 bond scission in organic nitramines occurs in high yields by reaction with 1,4-dihydronicotinamides. HMX (3) and tetryl (4) were used as model aliphatic and aromatic nitremines in reactions with 1-benzyl-1,4- dihydronicotinamide (BNAH, 1), resulting in hexamethylenetetramine and N- methylpicramide (5), respectively, as the predominant products. Radical initiation of the electron-transfer denitrohydrogenation mechanism is achieved either by photolysis or chemically by dithionite ion. A polymer- supported analogue of BNAH effects similar, though slower, N-denitration.
Elucidating the Reaction Mechanisms between Triazine and Hydrogen Sulfide with pH Variation Using Mass Spectrometry
Wang, Xiaoting,Zheng, Yajun,Shi, Jun,Gong, Xiaoyun,Ji, Yue,Han, Weiwei,Jiang, You,Austin, Daniel E.,Fang, Xiang,Zhang, Zhiping
, p. 11138 - 11145 (2018)
Triazine is one of the most economical and effective scavengers for hydrogen sulfide (H2S) removal, but the reaction mechanisms between triazine and H2S with pH variation in solution are still poorly understood. Herein, we show that the reaction process can be directly probed by means of paper spray mass spectrometry, in which an aprotic solvent (e.g., acetonitrile) is more favorable to the observation of reaction intermediates than a protic solvent (e.g., methanol), because of hydrogen bond interaction. Varying the pH of the reaction leads to completely different reaction pathways. With the pH in the range of 5.58 to 7.73, the major product was thiadiazine. With a pH of 3.02-3.69, thiadiazine is converted to 2-(5-(2-hydroxyethyl)-1,3,5-thiadiazinan-3-yl)acetaldehyde, which differs from the traditional pathway of analogous reactions. However, as ammonia was added into the reaction and the pH was adjusted to the range 8.45-9.43, triazine readily undergoes hydrolysis, and the formed intermediate reacts with ammonia and formaldehyde generated in situ from triazine to produce 1-(2-hydroxyethyl)-3,5,7-triaza-1-azoniatricyclo [3.3.1.13,7]decane (HTAD). Further increasing the pH up to 10.27-11.21 leads to the decomposition of HTAD. Based on the experimental observation and evidence from high-resolution and tandem mass spectrometry, we propose the plausible reaction mechanisms between triazine and H2S, as well as the derived reaction from triazine under different pH conditions.
Baur,Rueetschi
, p. 754,761,764 (1941)
The first controlled reduction of the high explosive RDX
McHugh, Callum J.,Smith, W. Ewen,Lacey, Richard,Graham, Duncan
, p. 2514 - 2515 (2002)
The first reduction chemistry of the high explosive RDX that allows subsequent functionalization into a SERRS active species.
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Koehn
, p. 903 (1899)
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Rombaut,Nieuwland
, p. 2061 ()
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Hexamethylenetetramine carboxyborane: synthesis, structural characterization and CO releasing properties
Ayudhya,Raymond,Dingra
, p. 882 - 889 (2017)
Carbon monoxide, although widely known as a toxic gas, has received great attention in the past few decades due to its promising role as a medical gas. Several classes of carbon monoxide releasing molecules (CORMs) have been synthesised with many of them having pharmacological activities under physiological conditions. Herein, we report the synthesis and structural characterization of the first example of amine carboxyborane that releases CO under physiological conditions without the aid of inducers. A representative compound hexamethylenetetramine carboxyborane (HMTA-CB) described here has a half-life of 2.7 days and gradually releases CO with the rate constant of 3.0 × 10?6 s?1. Its ability to promote cell growth shows the beneficial effect of slow CO release to supplement CO in small amounts over time.
Synthesis of 14C-labeled octahydro-1,3,5,7-tetranitro-1,3,5,7- tetrazocine (HMX)
Huang, Chi-Yu,Mah, Robert A.,Que Hee, Shane S.
, p. 377 - 385 (1998)
The 14C-uniformly labeled (UL) explosive, octahydro-1,3,5,7- tetranitro-1,3,5,7-tetrazocine (HMX) was synthesized in 40% yield by nitrolysis of 14C-labeled hexamethylenetetramine (hexamine) in the presence of boron trifluoride diethyl etherate as catalyst. The labeled hexamine was synthesized in 77% yield from 14C-labeled formaldehyde and ammonium hydroxide. The specific activity of 14C-labeled HMX was 0.24 mCi/mmol, a total of 58 μCi was prepared. The radiochemical purity of the labeled substance was 95% by HPLC-Liquid scintillation counting and 98% by HPLC-UV at 232 nm.
Consistency of NMR and mass spectrometry determinations of natural- abundance site-specific carbon isotope ratios. The case of glycerol
Zhang,Trierweiler,Jouitteau,Martin
, p. 2301 - 2306 (1999)
Quantitative determinations of natural-abundance carbon isotope ratios by nuclear magnetic resonance (SNIF-NMR) have been optimized by appropriate selection of the experimental conditions and by signal analysis based on a dedicated algorithm. To check the consistency of the isotopic values obtained by NMR and mass spectrometry (IRMS) the same glycerol samples have been investigated by both techniques. To have access to site-specific isotope ratios by IRMS, the products have been degraded and transformed into two derivatives, one of which contains carbons 1 and 3 and the other carbon 2 of glycerol. The sensitivity of the isotopic parameters determined by IRMS to fractionation effects possibly occurring in the course of the chemical transformations has been investigated, and the repeatability and reproducibility of both analytical chains have been estimated. The good agreement observed between the two series of isotopic results supports the reliability of the two different approaches. SNIF-NMR is therefore a very attractive tool for routine determination, in a single nondestructive experiment, of the carbon isotope distribution in glycerol, and the method can be applied to other compounds. Using this method, the isotopic distributions have been compared for glycerol samples, obtained from plant or animal oils, extracted from fermented media, or prepared by chemical synthesis. Typical behaviors are characterized.
Naked fluoride ion sources: Synthesis, characterization, and coupling reaction of 1-methylhexamethylenetetramine fluoride
Gnann, Robert Z.,Wagner, Ross I.,Christe, Karl O.,Bau, Robert,Olah, George A.,Wilson, Wiliam W.
, p. 112 - 115 (1997)
Anhydrous 1-methylhexamethylenetetramine (also referred to as N-methylurotropinium or methylhexaminium) fluoride was prepared by either halogen exchange between the corresponding iodide and AgF or by a single-step, one-pot, self-assembling synthesis from aqueous CH3NH2, HF, formaldehyde, and NH3. It was characterized by NMR and vibrational spectroscopy. Its hydrate undergoes at 70 °C a Sommelet-type ring opening and coupling reaction to form a potential cryptand system consisting of two bicyclic triazine groups that are connected through a methylene bridge and contain eight ternary nitrogen atoms. The compound was characterized by multinuclear NMR and vibrational spectroscopy, and its structure was determined from single-crystal X-ray diffraction data.
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Richmond,Myers,Wright
, p. 3659,3663 (1948)
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METHODS FOR PREPARING FORMALDEHYDE FROM CARBON DIOXIDE
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Paragraph 0017, (2020/11/27)
The present disclosure provides, inter alia, methods for preparing formaldehyde from carbon dioxide using bis(silyl)acetals, methods for incorporating carbon derived from carbon dioxide into a complex organic molecule derived from formaldehyde using bis(silyl)acetals, and methods for generating an isotopologue of a complex organic molecule derived from formaldehyde using bis(silyl)acetals.
Selective Conversion of Carbon Dioxide to Formaldehyde via a Bis(silyl)acetal: Incorporation of Isotopically Labeled C1 Moieties Derived from Carbon Dioxide into Organic Molecules
Rauch, Michael,Strater, Zack,Parkin, Gerard
supporting information, p. 17754 - 17762 (2019/11/05)
The conversion of carbon dioxide to formaldehyde is a transformation that is of considerable significance in view of the fact that formaldehyde is a widely used chemical, but this conversion is challenging because CO2 is resistant to chemical transformations. Therefore, we report here that formaldehyde can be readily obtained from CO2 at room temperature via the bis(silyl)acetal, H2C(OSiPh3)2. Specifically, formaldehyde is released from H2C(OSiPh3)2 upon treatment with CsF at room temperature. H2C(OSiPh3)2 thus serves as a formaldehyde surrogate and provides a means to incorporate CHx (x = 1 or 2) moieties into organic molecules. Isotopologues of H2C(OSiPh3)2 may also be synthesized, thereby providing a convenient means to use CO2 as a source of isotopic labels in organic molecules.
Iodopropynyl a, 1,4-butyne diol and hexamine three cogeneration method for continuous production of
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Paragraph 0041-0052, (2017/06/19)
The invention discloses a trigeneration continuous production method for propiolic alcohol, 1,4-butinodiol and urotropine, and belongs to the technical field of chemical engineering. According to the method, a formaldehyde aqueous solution (10%-37% wt) and acetylene are taken as raw materials for synthesizing propiolic alcohol and co-producing 1,4-butinodiol and urotropine, the reaction temperature is 80-120 DEG C, the pressure is 1.0-2.5 MPa, and propiolic alcohol with the purity of 99.5% or more, a 1,4-butinodiol aqueous solution and a urotropine aqueous solution are obtained. The conversion rate of formaldehyde in the whole technology is 100%, and the method has the advantages of safety and environment friendliness.
