- Kinetics and thermodynamics of the gas phase reaction SO3 + NH3 + N2 ? H3NSO3 + N2
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The kinetics of the gas phase reaction SO3 + NH3 + N2 ? H3NSO3 + N2 were studied with a flow reactor coupled to a chemical ionization mass spectrometer for detection of SO3 and H3NSO3. The rate coefficient for the association reaction SO3 + NH3 + N2 was measured as a function of temperature (280-340 K) and pressure (20-80 Torr of N2). Analysis of the SO3 decay and H3NSO3 appearance at higher temperatures yielded rate coefficients for H3NSO3 decomposition and the enthalpy of the reaction SO3 + NH3 ? H3NSO3: ΔH°298K = -24 ± 1 kcal mol-1.
- Lovejoy, Edward R.
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Read Online
- Introducing a mixed-valent dirhodium(ii,iii) catalyst with increased stability in C-H amination
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A new mixed-valent Rh2II,III dimer, [Rh 2(espn)2Cl] (espn2- = α,α, α′,α′-tetramethyl-1,3-benzenedipropanamidate), is reported. This compound readily dissociates Cl- at low concentrations in solution to form the active [Rh2(espn)2]+ catalyst, which performs intramolecular C-H amination with TONs > 1400. This work expands the scope of Rh2II,III dimers to nitrenoid chemistry.
- Kornecki, Katherine P.,Berry, John F.
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p. 12097 - 12099
(2013/01/16)
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- Mechanisms of hydrolysis of phenyl- and benzyl 4-nitrophenyl-sulfamate esters
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The kinetics of hydrolysis at medium acid strength (pH interval 2-5) of a series of phenylsulfamate esters 1 have been studied and they have been found to react by an associative SN2(S) mechanism with water acting as a nucleophile attacking at sulfur, cleaving the S-O bond with simultaneous formation of a new S-O bond to the oxygen of a water molecule leading to sulfamic acid and phenol as products. In neutral to moderate alkaline solution (pH ≥ ～ 6-9) a dissociative (E1cB) route is followed that involves i) ionization of the amino group followed by ii) unimolecular expulsion of the leaving group from the ionized ester to give N-sulfonylamine [HNSO2] as an intermediate. In more alkaline solution further ionization of the conjugate base of the ester occurs to give a dianionic species which expels the aryloxide leaving group to yield the novel N-sulfonylamine anion [ -NSO2]; in a final step, rapid attack of hydroxide ion or a water molecule on it leads again to sulfamic acid. A series of substituted benzyl 4-nitrophenylsulfamate esters 4 were hydrolysed in the pH range 6.4-14, giving rise to a Hammett relationship whose reaction constant is shown to be consistent with the E1cB mechanism.
- Spillane, William J.,Thea, Sergio,Cevasco, Giorgio,Hynes, Michael J.,McCaw, Cheryl J. A.,Maguire, Neil P.
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supporting information; experimental part
p. 523 - 530
(2011/03/17)
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- Preparation of N1-(2'-pyridyl)-1,2-propanediamine sulfamic acid and its use in the synthesis of biologically active piperazines
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A process for making an N1-(2′-pyridyl)-1,2-alkanediamine sulfamic acid of formula II by reacting a compound of formula I with NH2R′ wherein R and R′ are as defined in the specification. The invention also includes the compound of formula II, and optical isomers thereof. The compound of formula II is an intermediate useful for making chiral piperazine derivatives which are active at the 5-HT1A receptor.
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- Kappa agonist compounds and pharmaceutical formulations thereof
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Compounds having kappa opioid agonist activity, compositions containing them and method of using them as analgesics are provided. The compounds of formula IIIB have the structure: wherein R1, R2, R, Ar and n are as described in the specification.
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- Compositions of matter having bioactive properties
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Particles of coordinated complex comprising a basic, hydrous polymer and a capacitance adding compound, as well as methods for their production, are described. These complexes exhibit a high degree of bioactivity making them suitable for a broad range of applications through their incorporation into conventional vehicles benefiting from antimicrobial and similar properties.
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- Kappa agonist compounds and pharmaceutical formulations thereof
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Compounds having kappa opioid agonist activity, compositions containing them and method of using them as analgesics are provided. The compounds of formulae I, II, IIA, III, IIIA, IIIB, IIIB-i, IV and IVA have the structure: wherein R1, R2, R3, R4; and X, X4, X5, X7, X9; Y, Z and n are as described in the specification.
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- Methods and compositions controlling biofouling using sulfamic acids
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The invention relates to a method to inhibit bacteria from adhering to a submergible surface. The method contacts the submergible surface with an effective amount of at least one sulfamic acid or salt thereof to inhibit bacterial adhesion to the submergible surface. The invention also relates to a method for controlling biofouling of an aqueous system. This method adds an effective amount of at least one sulfamic acid or salt thereof to inhibit bacteria from adhering to a submerged surface within the aqueous system. This method effectively controls biofouling without substantially killing the fouling organisms. The sulfamic acid used in the method of the invention has the formula R1R2NS(O)2(OH). In this formula, R1and R2are independently a hydrogen, a C4-C20alkyl group or a cyclohexyl group. However, R1and R2are not both hydrogen. Alternatively, R1and R2, together with the N, may also form a 5-8 membered heterocyclic ring having the formula: In the heterocyclic ring, X is O, NH, or CH2. The salt of sulfamic acid can be an acid salt or quaternized sulfamic acid salt. The present invention also relates to a composition containing sulfamic acids or salts thereof useable in the above methods. The compositions comprise at least one sulfamic acid or salt thereof in an amount effective to inhibit bacteria from adhering to submergible or submerged surfaces.
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- Pharmaceutical compounds
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Pharmaceutical compounds of the formula STR1 in which R1 and R2 are each hydrogen, hydroxyl, halo, C1-4 alkyl, C1-4 alkoxy, acyloxy, --O-glucoside, optionally substituted phenyl or optionally substituted phenyl-C1-4 alkoxy; R3 is tetrazolyl, or and R4 and R5 are each hydrogen, hydroxy, acyloxy, nitro, C1-4 alkyl, C1-4 alkoxy, halo, optionally substituted phenyl, --SO3 H or --NR'R" where R' and R" are each hydrogen or C1-4 alkyl; provided that when R3 is --CR'R".CHR'"CO2 H or tetrazolyl, R1 and R2 are each hydroxyl, halo, C1-4 alkyl, C1-4 alkoxy, acyloxy, --O-glucoside, optionally substituted phenyl or optionally substituted phenyl C1-4 alkoxy; and or a pharmaceutically acceptable salt or ester thereof.
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- Preparation of aminoazo dyes
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Aminoazo dyes are prepared from the corresponding N-sulfomethylated aminoazo dyes by aqueous acid hydrolysis in the presence of amidosulfuric acid, urea or mixtures thereof.
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- F-substituted-3-β-D-ribofuranosyl-3H-imidazo[4,5-b]pyridines and pharmaceutical compositions thereof
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This invention discloses a group of compounds of formula (I) STR1 wherein R1 is hydrogen, halo, C1-4 alkyl, C1-4 alkoxy, COOR4 (R4 is H or C1-4 alkyl) or trifluoromethyl; R2, R5 and R6 are the same or different and can be hydrogen, hydroxy, OCOR7 (wherein R7 is hydrogen, C1-4 alkyl, phenyl optionally substituted) or halo; and R3 is hydrogen, COR4, C3-6 cycloalkyl or C1-4 alkyl or alkenyl; R2 may also be a phosphate group and pharmaceutically acceptable salts thereof which have been found to have analgesic activity. In addition, these compounds have antiinflammatory, antipyretic, antihypertensive and vasodilatory activity in varying degrees. Some of these compounds also have antiprotozoal and antiviral properties.
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- Kinetics of the Reaction between Hydroxylamine and Sodium Bisulfite
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Hidroxylamine and sulfur dioxide react in aqueous solution to form either sulfamic acid or ammonium bisulfate.Rate studies have been performed as a function of temperature.The rate law has been determined.The enthalpy and entropy of activation for the formation of both sulfamic acid and ammonium bisulfate have been evaluated.
- Gomiscek, S.,Clem. R.,Novakov, T.,Chang, S. G.
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p. 2567 - 2569
(2007/10/02)
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- Hydroxypropylene-amino-phosphonic-sulfonic acids
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This invention relates to compounds characterized by the presence of N-methyl, or substituted methyl, phosphonic acid and N-hydroxy-propylenesulfonic acid groups. These compounds contain at least one or more of each group and are bonded to the same or different amino groups. They are derived by reacting an amine with both (1) an epihalohydrin-bisulfite addition product and (2) with a carbonyl compound, such as formaldehyde, and phosphorous acid or its equivalent. They have a wide variety of uses, for example as scale and corrosion inhibitors, iron oxide removers, chelating agents, etc.
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- Disazo dyes having a benzthiazolyl substituted phenol or naphthol coupling component
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Disazo dyes containing a benzthiazolyl group and corresponding to the general formula: STR1 in which A and G are optionally substituted phenyl or naphthyl, D is derived from an optionally substituted salicylaldehyde or o-hydroxy-naphthaldehyde and E is derived from an optionally substituted o-aminothiophenol are provided. Metal modified polypropylene dyed with the disazo dye has excellent fastness properties.
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- Disazo dyes derived from 1-acyl-2,4-dihydroxybenzenes and metallized polyolefin dyed therewith
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Disazo dyes of the general formula: STR1 are provided where A is phenyl, naphthyl, phenyl substituted by up to 3 substituents or naphthyl substituted by up to 2 substituents; D is phenyl, naphthyl, or phenyl or naphthyl substituted by up to 2 substituents selected from alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms or halogen and X is alkyl of 1-4 carbon atoms, benzyl or phenyl. The dyes when applied to metallized polyolefin fabrics, particularly nickel-containing polypropylene fabrics, produce strong bright shades which are exceptionally fast to light, dry cleaning, crocking, gas and heat.
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- Bisazomethine dyes for metal-modified polyolefins
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Bisazomethine dyes of the general formula: STR1 in which A and D are optionally substituted benzene or naphthalene nuclei, E is an optionally substituted salicylaldehyde or o-hydroxynaphthaldehyde nucleus and G is an optionally substituted 2-aminopyridine nucleus. Metal-modified polypropylene dyed with the bisazomethine dye has excellent fastness properties.
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