Excess Of Nitric Acid Research Articles

Nitration of 3-methyl-1,5-diphenylpyrazole and related compounds

Addition of nitric acid (1 mole) to 3-methyl-1,5-diphenylpyrazole (I) in sulphuric acid at 0°, gives the 5-p-nitroderivative (III), which, with excess of nitric acid is converted into the 1,5-di-p-nitro-derivative (VI). Nitrating mixture at 100° introduces a third nitro-group into the 4-position of the pyrazole nucleus. Acetyl nitrate converts (I) into the 4-nitro-compound (X) which, on further stepwise nitration with nitrating mixture, gives first 3-methyl-4-nitro-5-m-nitrophenyl-1-phenylpyrazole (XV) and then 3-methyl-4-nitro-5-m-nitrophenyl-1-p-nitrophenyl-pyrazole (XVII). Various other mono- and di-nitro-compounds have been prepared, and their further nitration has been investigated. Nitration of 4-bromo-3-methyl-1,5-diphenylpyrazole (II) takes a similar course, and the products are identical with those from the bromination of the mono- and di-nitro-compounds from (I). Replacement of bromine by a nitro-group occurred during the nitration of 4-bromo-3-methyl-1,5-di-p-nitrophenylpyrazole (VI) at 100°. Structures were established by chemical methods, supported, where desirable, by n.m.r. spectroscopy.

Lactone Carboxylic Acids. VI. A Synthesis of α,β-Epoxybutyrolactone via α-Diazolactones

Abstract Reaction of α-carboxy-β-carbethoxy-γ,γ-dimethylbutyrolactone (3) with equimolar amount of nitrous acid gave ethyl α-hydroxyaminoaconate (7). However, the nitrosation of 3 using excess nitrous acid afforded a variety of compounds such as α-diazo (4 and 5), α-nitro (8), and α-azoxybutyrolactone (9) derivatives. Each of the products (4, 5, 8, and 9) could be synthesized from 7, independently. By the action of phosphoric acid, α-diazolactones (4 and 5) were converted into ethyl α,β-epoxyparaconate (6). The nature of the product 7 was demonstrated through its conversion into ethyl α-hydroxyaconate and through its thermal decomposition to ethyl α-aminoaconate and a-isopropylidenecyanoacetic acid derivatives. A possible mechanism for the formation of 6 through 4 and 5 is described.

Synthesis and antimicrobial action of α-(5-nitrofuryl-2)quinoxaline and its derivatives

α-(5-Nitrofuryl-2) quinoxaline, and its α′-cyano- and α′-oxyderivative were synthesized by nitration of the respective furylquinoxalines with a nitrating mixture. When 2-oxy-3-(furyl-2) quinoxaline is subjected to nitration with excess of nitric acid a dinitro-derivative is formed which is presumably 6-nitro-3-(5-nitrofuryl-2)-2-oxyquinoxaline. The antibacterial, tuberculostatic, and fungistatic activities of the α-(furyl-2)- and α-(5-nitrofuryl-2) quinoxalines and their derivatives were studied “in vitro.”

Studies of Nucleosides and Nucleotides. XXXVII. Synthesis of 8-Oxyguanosine Nucleotides and Uric Acid 9-Riboside 5'-Phosphate

8-Oxyguanosine 5'-mono-, 5'-di- and 5'-tri-phosphate were synthesized from 2', 3'-O-isopropylidene-8-oxyguanosine by the phosphorylation with P1-diphenyl, P2-morpholinopyrophosphoro chloridate, follwed either by acidic removal of the protecting group, reaction with inorganic phosphate in the presence of DCC, or by the reaction of its morpholidate with pyrophosphate. 5'-Monophosphate was hydrolyzed by the catalysis with snake venom 5'-nucleotidase. 8-Oxyguanosine 2', 3'-cyclic phosphate, which was obtained by the direct phosphorylation method from 5'-O-acetyl-8-oxyguanosine, was completely resistant against pancreatic RNase and RNase T1. Deamination of 8-oxyguanosine and its monophosphate was investigated. In the presence of excess nitrous acid a rapid loss of ultraviolet absorption was observed. With the use of limited amount of nitrous acid, uric acid 9-riboside 5'-monophosphate was obtained.

L'application des radioisotopes a la chromatographie sur colonnes de celluloses substituees—IV : L'analyse du mercure et du zinc dans le bismuth

The Chromatographie behaviour of nanogram amounts of bismuth has been studied by radioisotope techniques on cellobiose, cellulose and seven substituted celluloses. All celluloses in ethyl ether adsorb bismuth, provided that it is as nitrate, and that excess of nitric acid is avoided. Bismuth can be eluted with thiocyanate in ethermethanol or with hydrochloric acid in methanol, depending on the retention strength of the various functional groups of celluloses. A very simple method of separation of bismuth from mercury over a wide range of concentration is presented.

Thin Films Grown on Silicon Surfaces by Excess Nitric Acid Process

not Available.

Nitration of models of lignin containing benzyl alcohol and alkyl benzyl ether groupings

1. Models of lignin-α-ethylveratryl alcohol (II), its methyl ether (VI), andα-ethyl-4-hydroxy-3-methoxy-benzyl alcohol methyl ether (V)-were nitrated with concentrated HNO3 in CCl4 and in dry ether. 2. In the nitration ofα-ethyl-4-hydroxy-3-methoxybenzyl alcohol methyl ether (V) the side chain in the para position relative to the phenolic hydroxyl is replaced by the nitro group with formation of 4,6 -dinitroguaiacol. 3. In the nitration ofα-ethylveratryl alcohol methyl ether (VI) the main factor determining the course of reaction is the molar ratio of the substance being nitrated and HNO3. With a 1∶ 3 ratio the nitro group enters the 6-position of the aromatic nucleus, with a 1∶6 ratio nitration of the nucleus is accompanied by the replacement of the benzyl ether grouping by a nitric ester grouping, and at ratios of 1∶9 and 1∶12 there are two cmpeting reactions: replacement of the side chain by a nitro group and the formation of the mononitro compound nitrate (IV) in the first case and the dinitro compound nitrate (IX) in the second. In the nitration ofα-ethylveratryl alcohol (II) with 6–12 molecular proportions of HNO3 the same, nitro compounds were obtained as in the nitration of (VI). 4. It may be supposed that a) the formation of nitric ester groupings in nitrolignin is due to the esterification of benzyl alcohol hydroxyls and the replacement of benzyl ether groupings by ester groupings, and b) the nitration of lignin with a considerable excess of nitric acid is accompanied by degradation with replacement of side chains containing benzyl alcohol or benzyl ether groupings by nitro groups.

An Improved Ammonium Molybdophosphate Method for Phosphorus in Fertilizers

Abstract The official volumetric method for phosphorus in fertilizers was modified to improve its accuracy and precision. Sulfate interference is eliminated by addition of excess nitric acid before precipitation of the molybdophosphate. The precipitate is filtered on a glassfiber pad, and when it is dissolved in alkali, formaldehyde is added to complex the ammonia; a mixed indicator (methyl green-phenolphthalein) is used that changes color at the equivalence point. The modified method passed Youden’s ruggedness test and gave results in excellent agreement with those of the gravimetric quinolinium method in analyses of standard phosphate rocks, primary phosphate standards, and fertilizers.

Photometric determination of trace of manganese in uranium metal

Determination of a trace of manganese contained in uranium metal has been made by the spectrophotometric method with permanganate. The sample is dissolved in hydrochloric acid and excess nitric acid. Hydrochloric acid is removed by evaporation. Urarium is separated from a nitric acid (4N to 6N) solution with TBP--CCl/sub 4/. Sulfuric acid is added, and the solution is heated to fume; water, silver nitrate, and ammonium persulfate solution are added and boiled. Manganese in the sample solution is oxidized to permanganate. The color of permangaanate is measured by the light transmittancy at 525 m mu . When 2 g of the sample is taken and the volume of permanganate solution is made up to 10 ml, as low as 2 ppm manganese in uranium metal can be detemnined. (auth)

Behavior of lignin models on nitration

1. The behavior of eight lignin models under the action of concentrated nitric acid in a carbon tetrachloride medium was studied; the models were derivatives of 1-(3,4-dlmethoxyphenyl)- and 1-(4-hydroxy-3-methoxyphenyl)-propane containing a hydroxy group in various positions in the propane chain. 2. In the nitration of models having an etherified phenolic hydroxyl [(3,4-dimethoxyphenyl)propanols], one nitro group entered the nucleus in the 6-position. The action of nitric acid favored also the condensation of the alcohol in which the OH was in the 1-position of the side chain, and it oxidized the alcohol group of 1-(3,4-dimethoxyphenyl)-2-propanol to a keto group. 3. When treated with nitric acid under similar conditions, models with a free phenolic hydroxyl in the para position to the side chain (derivatives of 4-propylguaiacol) behave differently: 1-(4-hydroxy-3-methoxyphenyl)-1-propanol, treated with excess of nitric acid (3 molecular proportions), loses its side chain and gives 4,6-dinitroguaiacol; under the action of a smaller amount of nitric acid 4,6-dinitroguaiacol is accompanied by some dimeric condensation product. When 3-methoxyphenyl)-1-propanol is nitrated, a light-brown powder containing nitrogen is formed. 4. The behavior of the models in nitration indicates the great variety of the process that occur when lignin is treated with nitric acid, for all the types of models studied are present in lignin as structural units.

台湾コブラ蛇毒の化学的研究 (第6報)

Kinetic studies were made on the reaction of nitrous acid and lecithinase, purified from Formosan cobra venom. The decreased activity of lecithinase in the presence of excess nitrous acid in acetate buffer is a first-order reaction and its reaction rate is extremely slow as compared to deamination reaction, the half-life being 270 minutes at pH 4.0 and 390 minutes at pH 4.4. The lecithinase partially inactivated by nitrous acid does not recover its activity by application of hydrogen sulfide. These facts suggest that the principle of lecithinase activity is independent of amino or mercapto group and is situated in the phenol, that is, in tyrosine.

有機化合物中の硫黄の定量法の研究 (第1報)

Sulfur in organic compounds was determined by the following procedures. The sample was heated with fuming nitric acid in a sealed tube, the cooled content was transferred to an evaporating dish, evaporated on a water bath to remove excess nitric acid, and barium chromate added to the acid solution to precipitate barium sulfate. Neutralization followed by filtration resulted in the presence of chromic acid ion corresponding to the sulfate ion and the filtrate was titrated with 0.05N ferrous sulfate, using barium diphenylaminosulfonate as the indicator. The endpoint of this titration was somewhat more clear than by other existing method. The semimicro- and micro-analyses gave good results, the maximum error being 0.30% and 0.29%, respectively.

Studies on Analysis of Calcium Cyanamide. (I·II)

Results of quantitative estimation of dicyandiamide in calcium cyanamide by various methods do not always give agreement and there are considerable variation. Furthermore, these methods require a considerable time and there are many difficulties in their practical application. The present report deals with the studies on the effects of the amount of sample used, concentration of reagents, presence of impurities, and pH at the time of precipitation temperature and tiltrating condition in Harger or silver picrate method with the result that this is inaccurate in the presence of impurities, e. g. melamine and guanidine; a suitable to be applicable in such a case is established with higher accuracy and rapidity in comparison with heretofore known methods. A preliminary report on the corrected values of sulubilities is given.An improved Harger described in the first report gave accuracy and rapidity. However, the was not ideal in point of rapidity and further studies revealed that a satisfactory result was obtained by application of the formation of guanylurea nitrate from reaction of nitric acid. The is to add a certain amount of nitric acid to an extracted solution of calcium cyanamide, heat the mixture in a sealed container for 15 minutes at 100°C, the excess of nitric acid being estimated by titrating it with sodium hydroxide with an aim of estimations the amount of dicyandiamide from the amount of nitric acid consumed for the reaction. The time required for the reaction is 3 hours including the extraction, it does not require special reagents and its accuracy is ±3% of the content.

The Reaction of Amino Acids and Proteins with Diazonium Compounds. I. A Spectrophotometric Study of Azo-Derivatives of Histidine and Tyrosine.

The coupling in alkaline solution of free histidine and tyrosine with p-diazobenzene-sulphonic acid has been studied as a basis for quantitative investigation of the behaviour of proteins in the presence of diazonium compounds. Both mono- and bisazo- derivatives may be formed with each amino acid, the wavelengths of maximum absorption being 380 and 490 mμ respectively for histidine and 325 and 480 mμ respectively for tyrosine ; the wavelength displacements on accepting a second diazonium group are comparable to effects reported for similarly conjugated systems. When appropriate corrections are made for other absorbing components, the extinctions at 490 mμ and the initial histidine concentrations up to the (bis) equivalent of diazonium compound conform to Beer's law, showing that bis(azobenzenesu1phonic acid)histidine is formed exclusively under these conditions. At higher histidine concentrations mono(azobenzenesulphonic acid)histidine is formed in increasing proportions. Even at low initial tyrosine concentrations both mono- and bis(azobenzenesulphonic acid)-tyrosine are formed, although mono-coupling is again favoured more as the concentration increases. No direct reaction between histidine and the nitrous acid used in the formation of the diazonium compound could be detected spectrophotometrically, but diazotization of tyrosine appears to reduce the propensity for bis-coupling to some extent. If urea is incorporated in the system to destroy excess nitrous acid, a yellow compound having maximum absorption at 430 mμ is formed between p-diazo-benzenesulphonic acid and the urea.

Pteridine Chemistry. II. The Action of Excess Nitrous Acid Upon Pteroylglutamic Acid and Derivatives

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPteridine Chemistry. II. The Action of Excess Nitrous Acid Upon Pteroylglutamic Acid and DerivativesRobert B. Angier, James H. Boothe, John H. Mowat, Coy W. Waller, and Joseph SembCite this: J. Am. Chem. Soc. 1952, 74, 2, 408–411Publication Date (Print):January 1, 1952Publication History Published online1 May 2002Published inissue 1 January 1952https://doi.org/10.1021/ja01122a036RIGHTS & PERMISSIONSArticle Views104Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (548 KB) Get e-Alerts Get e-Alerts

A New Isotope of Tungsten

A search for tungsten radio-isotopes was made using a 5-mil tantalum foil which had received 80 micro-ampere-hours bombardment with approximately 20 MeV. deuterons from the 60-in. Crocker Laboratory cyclotron. The foil was dissolved in nitric acid containing five per cent of hydrofluoric acid. A few milligrams of tungsten carrier was added, and after removal of hydrofluoric acid by fuming with sulphuric acid, the tantalum was precipitated by sodium hydroxide and the precipitate digested with hot alkali. Tungsten was precipitated from the alkaline solution by boiling with excess nitric acid. The procedure was repeated until the tantalum-scavenging carrier precipitates were inactive.

Researches on the alkoxy‐amino‐nitrobenzenes. III: Nitration of 1‐alkoxy‐2‐aminobenzenes and 1‐alkoxy‐2‐acetylaminobenzenes

AbstractNitration of 1‐alkoxy‐2‐acetylaminobenzenes with an excess of nitric acid, sp. gr. 1.40, leads to a mixture of the 4‐nitro and the 5‐nitro derivative, in which the latter substance predominates.Nitration of 1‐alkyloxy‐2‐aminobenzenes or 1‐alkyloxy‐2‐acetylaminobenzenes with the calculated amount of nitric acid in concentrated sulphuric acid gives the 4‐nitro derivative as the sole or practically sole nitration product.The results obtained in the nitration are discussed from a theoretical point of view.

The Perchloric Method for the Determination of Sulfur in Rubber

Abstract The problem of the determination of sulfur in rubber has been dealt with extensively in the literature, and it seems as if discussions and descriptions of new technic are nowhere nearly ended yet. The determination is so essential, and its rapid and precise execution is of such importance in industrial technic, that efforts in this direction should not be regarded as wasted. In 1926 and in 1927 Le Caoutchouc et La Gutta-Percha contained two articles in which the present author discussed the conditions of the determination of sulfur in rubber and then proposed the use of a new oxidizing mixture, not mentioned previous to that time, which involved the destruction of organic substances by perchloric acid. This method consisted simply in the attack on a 1-gram sample of rubber by 10 cc. of nitric acid (d. 1.39) and 5 cc. of perchloric acid (d. 1.61). Upon heating, attack by the nitric acid takes place, and this is followed by evaporation of the excess nitric acid, then at a little higher temperature there is an attack by the perchloric acid, which oxidizes the rest of the organic substance completely. This publication was concerned much more, in the determination of sulfur by the perchloric method, with the general idea of the destruction of organic substances than it was with the precise details of carrying it out. The technic had been studied somewhat superficially, as is shown by the text of the article itself.

METHOD FOR THE ANALYSIS OF ALUMINOUS SILICATE REFRACTORIES1

A method is given in which the solution of difficultly fusible refractory material is obtained by subjecting the finely pulverized material to two fusions, the first in sodium carbonate, followed by one in potassium bisulphate. The melts are dissolved in water and after adding sulphuric acid are evaporated to dense fumes. Care is taken to remove any calcium sulphate that may be formed. The final residue is treated with hydrofluoric and sulphuric acids. The alumina is determined according to the method described by Blum as given by Hillebrand especial care being used in heating the final precipitate to constant weight. A temperature of about 1150°C is necessary. Two precipitations are required in the determination of lime. The excess of ammonium salts are removed prior to the precipitation of the magnesia, by adding an excess of nitric acid, evaporating to dryness and heating, which expels the ammonium chloride according to the reaction NH4Cl + HNO3= HCI + 2H2O + N2O.

5. On an Oxycyanide, and a New Oxide, of Bismuth

Bœdeker (Annalen, 123, 61), by the action of potassium cyanide on bismuth nitrate, obtained a reddish-brown salt, to which he assigned the formula Bi2O5.2H2O. In an examination of the oxides of bismuth in conjunction with Hoffmeister and Robbs (Chem. Soc. Jour., 1881; Proc., p. 21), I had occasion to prepare Bœdeker's salt; a slight study of its properties proved it to be a compound of no little interest. When a concentrated aqueous solution of potassium cyanide is added to a solution of metallic bismuth in excess of nitric acid, and the mixture is boiled, a brownish-red solid and a more or less dark red liquid are obtained, and quantities of hydrocyanic acid are evolved. When the excess of nitric acid is nearly neutralised by potash before addition of potassium cyanide, the colour of the solid is a much lighter brown, and the supernatant liquid is nearly or quite colourless.