100-97-0

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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-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.

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.

The first reduction chemistry of the high explosive RDX that allows subsequent functionalization into a SERRS active species.

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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.

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.

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.

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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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.

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.

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.

The invention discloses a method for producing industrial urotropine through taking waste paraformaldehyde as a raw material. The method comprises the steps of: reacting the waste paraformaldehyde solid which is separated out by a formaldehyde storage tank with ammonia water (or gaseous ammonia) under the pressurized condition to produce urotropine aqueous solution, wherein the molar ratio of paraformaldehyde (converted into formaldehyde) to ammonia is 6:(4.1-4.5); and decolorizing the aqueous solution, filtering, vacuum-concentrating, cooling and crystallizing, centrifuging and drying to produce urotropine, wherein the reaction pressure is 0.15-0.45Mpa, the reaction temperature is 115 DEG C-150 DEG C, the reaction time is 4-6 hours, the recovery rate of waste paraformaldehyde can reach above 98%, the content of the produced urotropine can reach 98%, and the water-insoluble matter is excellent.

We report herein the use of the (dihydrido)iron catalyst, Fe(H)2(dmpe)2, for the selective reduction of CO2 into either bis(boryl)acetal or methoxyborane depending on the hydroborane used as a reductant. In a one-pot two-step procedure, the in situ generated bis(boryl)acetal was shown to be a reactive and versatile source of methylene to create new C-N but also C-O and C-C bonds.

Forensic identification of batches of homemade explosives (HME) poses a difficult analytical challenge. Differentiation among peroxide explosives is reported herein using a colorimetric sensor array and handheld scanner with a field-appropriate sampling protocol. Clear discrimination was demonstrated among twelve peroxide samples prepared from different reagents, with a classification accuracy >98%.

Iminodiaziridines are synthesized, by (i) 1,3-dehydrochlorination with potassium, teri-butoxide of N-chloroguanidines, generated in situ from. N,N′,N″-substituted guanidines with tert-butyl hypochlorite, and (ii) base-mediated 1,3-elimination of sulfuric acid from N,N',N″- substituted hydroxyguanidine O-sulfonic acids. At elevated temperatures, (alkylimino)diaziridines undergo valence isomerization by 1,3shift, [2+1] cycloelimination to afford isocyanides and diazenes, and ring-opening elimination to yield alkylideneguanidines. N′-Aryl-N-hydroxyguanidine O-sulfonic acids furnish (N-arylimino)diaziridines, but no 1-aryl-3- iminodiaziridines, instead giving rearranged isomere. Precursors containing perdeuterated feri-butyl groups give rearranged products that show complete scrambling. This indicates that l-aryl-3iminodiaziridines are intermediates that undergo very rapid I degenerate valence isomerization. Provided that the ortho aryl positions are substituted, high yields of (arylimino)diaziridines are obtained, along with 2-imino-2,3-dihydro-3aHbenzimidazoles, Otherwise, 2-amino-lH-benzimidazoles and strongly fluorescent 3-amino-2H-indazoles, originating from rearrangements of the elusive l-aryl-3-iminodiaziridines, predominate. N',N″-Diaryl-N-hydroxyguanidine O-sulfonic acids give only rearranged products: a 2-amino-1H-benzimidazole and a 6-amino-5H-dibenzo[d,f][1. 3]diazepine if aryl = phenyl, or a 2-imino-2,3-dihydro-3aH-benzimidazole if aryl = mesityl. 3aH-Benzimidazoles slowly dimerize through Diels-Alder reactions. 15N NMR signals were assigned, to the syn and anti ring nitrogen atoms of iminodiaziridines with the help of a combination of homonuclear NOE and HNHMBC or HN-gHMBC experiments.

In situ 1H nuclear magnetic resonance spectroscopy was used to investigate the processes that occur during the synthesis of 1,3,6,8-tetraazatricyclo[4.3.1.13,8]undecane (TATU). NMR analysis showed a reaction mixture containing more than one compound. The production of these intermediates and collateral products was rationally supported by a careful 1H NMR monitoring study. We characterized 1,3,5-triazabicyclo[3.2.1]octane (TABO, 4) and 3-(2-aminoethyl)-1,3,5-triazabicyclo[3.2.1]octane (AETABO, 7) by 1H and 13C NMR in D2O solution inside the NMR sample tube, as an intermediate and collateral product of the reaction, respectively. Further, a reaction of 1,3,6,8-tetraazatricyclo[4.4.1.13,8]dodecane (TATD) with 15N-labeled ammonium chloride was carried out. The 15N NMR and GC-MS experiments indicated that 15N was incorporated into TATU, TABO, and urotropine.

Three-component condensations of formaldehyde with hydrogen sulfide and hydroxylamine or amino alcohols at a ratio of 3:2:1 give 47-73% of N-hydroxy(or hydroxyalkyl)-1,3,5-dithiazinanes. The reactions of CH2O with H 2S and hydroxylamine or α-amino alcohols at a ratio of 4:3:1 involve both amino and hydroxy groups, leading to the corresponding dithiazinanes. 4-Aminobutan-1-ol reacts with CH2O and H2S under analogous conditions only at the amino group to form 4-(1,3,5-dithiazinan- 5-yl)butan-1-ol.

The invention relates to novel 5-bromo-5-nitro-2-thienyl-1,3-dioxanes of the formula (I) in which R1, R2 and R3 are as defined in the description are highly suitable for use as biocides for protecting plants and industrial materials.

This invention is drawn to a process for isomerizing a non-equilibrium mixture of xylenes and ethylbenzene using a catalyst comprising a zeolite, a platinum-group metal and an aluminophosphate binder or silica, resulting in a greater yield of para-xylene at favorable conditions compared to processes of the known art.

The kinetics of oxidation of methionine (MT) by hexamethylenetetramine-bromine (HABR) has been studied in acetic acid. The reaction leads to- the formation of the corresponding sulphoxide. The reaction is first order in HABR. Michaelis-Menten type kinetics has been observed with respect to the methionine. The formation constants of the intermediate complex and the rate constants from its decomposition have been evaluated at different temperatures. The thermodynamic and activation parameters have also been evaluated. The addition of hexamine (HXA) has no effect on the rate. A mechanism involving the formation of a halogenosulphonium cation in the slow step has been proposed.

This invention is drawn to a process for isomerizing a non-equilibrium mixture of xylenes and ethylbenzene using an oil-dropped catalyst comprising a zeolite, a platinum-group metal and an aluminophosphate binder, resulting in a greater yield of para-xylene at favorable conditions compared to processes of the known art.

This invention provides a process for making crosslinked zein, comprising heating zein in the presence of water to a temperature of at least 130° C., with or without pressure, to induce crosslinking.

A process for decolorizing polyalkylene polyamines, which comprises contacting one or more polyalkylene polyamines having an average molecular weight of greater than about 200 and less than about 1000 with carbon at a temperature greater than or equal to about 100° C. and less than or equal to about 300° C. under conditions effective to reduce the color rating of the one or more polyalkylene polyamines.

Rate constants for the reaction of the phosphate radical (PO42-) with various aliphatic amines have been measured by flash kinetic spectrophotometry.Phosphate radical can react with aliphatic amines by hydrogen atom abstraction or electron transfer, the general reactivity order being tertiary secondary primary.For tertiary amines, a good correlation has been obtained when the logarithm of rate constants are plotted against the oxidation peak potentials of the amines, providing clear evidence for an electron transfer mechanism.In the case of tertiary amines, electron transfer from the nitrogen takes place.The identification of aminium cation radicals in the case of cyclic tertiary amines like, 1,4-diazabicyclooctane (DABCO) and 1,3,6,8-tetraazatricyclododecane (TATCD) provides additional proof for electron transfer.Primary and secondary amines get oxidized mainly by hydrogen atom abstraction as shown by the poor correlation with Taft substituent constants, but electron transfer cannot be completely ruled out.In the case of t-butylamine, electron transfer takes place and t-butylalcohol has been identified as the end product.

Eleven triaziridine derivatives were heated at 60 deg C in CDCl3 to obtain information on the tendency towards, resp. the resistance to, ring opening of the N3-homocycle by thermolysis.Among these triaziridines, there are three which contain, as one of the substituents, a methoxycarbonyl group (ester derivatives 1, 5, and 16), three a methyl group (methyl derivatives 18, 24, and 26), three an H-atom (14, 27, and 30), and two a negative charge (31 and 32).The other two substituents in each of these four classes of triaziridines are trans-located i-Pr groups (1, 18, 27, and 31), cis-located i-Pr groups (5, 24, 14, and 32), and a 1,3-cis-cyclopentylidene group (16, 26, and 30).As major products of these mild thermolyses, we isolated: from the trans-ester 1 and from the annellated ester derivative 16, the 1-acyl-azimines 2 and 17, respectively, from the cis-ester 5, the 3-acyl-triazene 4, from the trans-methyl derivative 18, the (E)-diazene 19 and hexamine 21, from the cis-methyl derivative 24 the 2-methylazimine 25, both from the trans- and cis-H-derivatives 27 and 14, respectively, the H-triazene 13 and, finally, both from the trans- and cis-anion 31 and 32, respectively - after protonation - the H-triazene 13 and - after methylation - the methyl-triazene 33.The same thermolysis of the annelated methyl and H-derivatives 26 and 30, respectively, resulted only in decomposition.These results can be uniformly interpreted with a primary opening of the triaziridine ring by rupture of one of the two types of N-N bonds leading to azimines or triazenide anions.Some of the azimines were isolable, namely 2, 17, and 25, and one was spectroscopically observable as an intermediate, namely 11 on the way to the triazene 4.The other azimines are plausible intermediates to the isolated products, namely 15 on the way to 13, and 22 on the way to 19 and 21.The triazenide anion 28 is the evident intermediate on the way to 13 or to 33.The annelated azimines are assumed not be formed from 26 and 30, or then to be decomposed under the conditions of their formation.We conclude that the triaziridine derivatives 1, 16, and 18 underwent thermal ring opening between N(1) and N(2), while the derivatives 5, 14, 24, 27, 31, and 32 were ruptured between N(2) and N(3); no conclusion was possible on the ring opening of the derivatives 26 and 30.The predominant formation of the (Z)-azimine 2 from the trans-triaziridine 1, and of the (E)-isomer 3 - among the two azimines - from the cis-triaziridine 5 suggests a stereospecificity in the triaziridine ring openings.This would, however, not be expected to be observable in the products from the other triaziridines, since both N-N bonds of the azimine 25 and of the anion 28 probably rotate rapidly and since the secondary transformations of the other primary products are not able to retain configurational information.

The reaction of methyl acrylate and acrylonitrile with formaldehyde dimethylhydrazone takes place both by a -cyloaddition path and by a -dipolar cycloaddition path.

Catalysts producing a sharply peaked alkoxylation distribution during the alkoxylation of organic materials comprise mixtures of BF3 and metal alkyls or metal alkoxides, SiF4 and metal alkyls or metal alkoxides, or mixtures of these catalysts.

Catalysts comprising mixtures of HF and metal alkoxides and mixed metal alkoxides produce a sharply peaked alkoxylation distribution during the alkoxylation of organic materials.

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Pechmann condensation of β-naphthol with ethyl acetoacetate in the presence of anhydrous aluminium chloride gives, besides two known compounds, 4-methyl-6,7-benzocoumarin and 3-methyl-9-hydroxyphenalen-1-one (I).The Duff reaction of β-naphthol gives the new compounds 1,3-diformyl-2-naphthol and 2-formyl-2,3-dihydro-1H-naphth-oxazine (II) and the known 2,2'-dihydroxy-1,1'-binaphthylmethane.Compound (II) exists as a mixture of rotamers.

This invention relates to a process for the preparation of compounds having the general formula: STR1 in which: R1 represents a hydrogen atom, an optionaly substituted alkyl, aryl or aralkyl radical; R2 and R3 are the same or different and represent independently a hydrogen atom, a lower alkyl, aryl or heterocyclic radical; and R4 represents a hydrogen atom or an alkyl, cycloalkyl, alkoxy carbonyl, carboxy, aryl or heterocyclic radical, comprising reacting a compound having the formula: STR2 in which R1, R2 and R3 are as defined above, with a compound having the formula: STR3 in which R4 is as defined above; X is a halogen atom, or an optionally substituted alkoxy, thioalkyl or amino group; and Y represents an optionally substituted alkoxy, thioalkyl or amino group, or a group of the formula: STR4 in which R is a lower alkyl or aryl radical; or both the groups X and Y, together with the carbon atom to which they are attached, form a 6-membered hexahydro-S-triazinic, trioxannic or trithianic heterocyclic nucleus, in an inert solvent, at a temperature between 0° and 150° C. and in an anhydrous medium, and, if desired, liberating the free base.