Showing papers on "Methanol published in 1971"

Reaction intermediates in methyl alcohol decomposition on ZnO

Abstract: The decomposition of methyl alcohol on ZnO was studied using infra-red spectroscopy during the course of the reaction. The concentrations and reactivities of the chemisorbed and gas phase species were measured as well as the overall reaction rate under various non-stationary conditions. When CD3OD vapour was introduced over ZnO, methoxide ion and formate ion were observed, and D2, CO2 and CO were evolved into the gas phase. When the CD3OD in the ambient gas was removed by a dry ice-methyl alcohol trap during the course of the reaction, the evolution of D2 and CO2 stopped, while the evolution of CO continued unchanged. At 240°C, the decomposition rate of the surface formate ion was in reasonable agreement with the rate of production of carbon monoxide. On releasing the trapped methanol, the rates of formation of CO2 and D2 increased again, surface methoxide reappeared, and the concentration of the surface formate ion decreased correspondingly. These results lead to the conclusion that CO was produced mainly by the decomposition of formate ion, and D2 and CO2 came from the reaction between CD3OD and DCOO(a).

Blood methanol concentrations during experimentally induced ethanol intoxication in alcoholics.

Abstract: Accumulation of methanol in blood was detected in alcoholic subjects during a 10- to 15-day period of chronic alcohol intake. Blood methanol levels increased progressively from 0.2 to 2.7 mg/100 ml from the 1st to 11th day of drinking, when blood ethanol concentrations ranged between 150 and 450 mg/100 ml. Blood ethanol was eliminated at the rate of 272 ± 3 mg/100 ml/hr within 14 to 18 hours after cessation of drinking. Blood methanol levels decreased at the rate of 0.29 ± 0.04 mg/100 ml/hr only after blood ethanol levels decreased to 70 to 20 mg/100 ml. Blood methanol disappearance lagged behind the linear disappearance of ethanol by approximately six to eight hours and complete clearance of blood methanol required several days. The pattern of accumulation and clearance of methanol and ethanol was similar for subjects who consumed either beverage alcohol (bourbon) or methanol-free grain alcohol. Methanol probably accumulates in the blood as a result of competitive inhibition of alcohol dehydrogenase by ethanol and the presence of endogenously formed methanol or its metabolites may contribute to the severity of intoxication and/or the alcohol withdrawal syndrome.

Direct Blood-Injection Method for Gas Chromatographic Determination of Alcohols and Other Volatile Compounds

Abstract: An extremely simple, rapid method is described for simultaneously determining methanol, ethanol, acetone, isopropanol, and low-boiling hydrocarbons associated with glue sniffing. Less than 1 µl of blood, mixed with an internal standard, is injected directly into a low-cost gas chromatograph equipped with a flame-ionization detector. No extraction, distillation, and (or) sample preparation is required, and the method is sensitive to less than 10 µg of alcohol per ml.

Pulse radiolysis studies of electron transfer in aqueous quinone solutions

Abstract: The transient absorption spectra observed on pulse radiolysis of neutral aqueous solutions containing p-benzoquinone and excess methanol, ethanol, isopropanol and formate, saturated with nitrous oxide are reported. The spectra are analogous to those obtained in solutions containing excess t-butanol and N2, O2, nicotinamide adenine dinucleotide or thymine and are attributed to the semiquinone radical-anion formed by electron transfer reactions with bimolecular rate constants k=ca. 109-1010 M–1 s–1. This assignment is supported by measurements of the acid dissociation constant of the absorbing product (pKa= 4.1) in solutions containing excess acetone and isopropanol.

Physiological Studies of Methane and Methanol-Oxidizing Bacteria: Oxidation of C-1 Compounds by Methylococcus capsulatus

Abstract: Methylococcus capsulatus grows only on methane or methanol as its sole source of carbon and energy Some amino acids serve as nitrogen sources and are converted to keto acids which accumulate in the culture medium Cell suspensions oxidize methane, methanol, formaldehyde, and formate to carbon dioxide Other primary alcohols are oxidized only to the corresponding aldehydes Oxidation of formate by cell suspensions is more sensitive to inhibition by cyanide than is the oxidation of other one carbon compounds This is due to the cyanide sensitivity of a soluble nicotinamide adenine dinucleotide-specific formate dehydrogenase Oxidation of formaldehyde and methanol is catalyzed by a nonspecific primary alcohol dehydrogenase which is activated by ammonium ions and is independent of pyridine nucleotides Some comparisons are made with a strain of Pseudomonas methanica

Dehydration of methanol and tert-butyl alcohol on silica-alumina

Abstract: The catalytic dehydration of tert-butyl alcohol and of methanol has been studied over silica-alumina Both reactions obey the rate law, v=kap½a/(1 +ap½a+bpw) Pyridine, Na+ and tetracyanoethylene poison the dehydration reactions These results show that the reaction requires both acidic and basic sites However, the dehydration of tert-butyl alcohol is much more sensitive to the presence of strongly acidic sites then the methanol dehydration Alumina, which has a basic character, is more active than silica-alumina for methanol dehydration These experimental results and those previously published in the literature accord with a conventional carbonium ion mechanism for the dehydration of tert-butyl alcohol A new mechanism which involves a nucleophilic attack by the alcohol molecule is proposed for the dehydration of methanol

Reaction of Formaldehyde and of Methanol with Xanthine Oxidase

Abstract: Earlier studies on inactivation of xanthine oxidase induced by methanol and accompanied by development of a specific electron paramagnetic resonance signal (the Inhibited signal) have been extended. The same reaction takes place when enzyme is treated with formaldehyde. With this, time-courses for signal development and disappearance of enzymic activity cannot be distinguished. Under a variety of conditions, disappearance of the signal accompanied by partial restoration of activity could be achieved. Side reactions also take place in the presence of formaldehyde. Electron paramagnetic resonance parameters of the Inhibited signal are reported. In the signal-giving species a single non-exchangeable proton interacts with Mo(V) in the enzyme active site. Experiments with C2H3OH and with 2HC2HO show that this proton is derived from the inactivating agent. It is proposed that a formyl residue, –CHO, becomes attached to a group in the active centre and that interaction of molybdenum with this residue stabilizes the five-valent state of the metal, thus preventing enzyme turnover. Methanol is presumed to be oxidized to formaldehyde at the active centre before taking part in the reaction.

The synthesis of 1-14C-arachidonate and 3-14C-docosa-7,10,13,16-tetraenoate

Abstract: Methyl 1-14C-arachidonate was prepared by coupling 1-bromotetradeca-2,5,8-triyne with 4-pentyn-1-ol to yield nonadeca-4,7,10,13-tetrayn-1-ol. This compound was reduced with Lindlars catalyst. The resulting alcohol was converted to the mesylate and then to the nitrile which in turn was converted to methyl 1-14C-arachidonate by hydrolysis with anhydrous HCl in methanol. The methyl 1-14C-arachidonate was reduced to the alcohol with LiA1H4 and converted to the mesylate which in turn was treated with diethyl malonate. Following saponification and decarboxylation 3-14C-docosa-7,10,13,16-tetraenoic acid was obtained.

Process for manufacturing iron molybdate catalysts of high strength and the use of the resulting catalysts in the catalytic oxidation of alcohols to aldehydes

Abstract: An iron molybdate catalyst is manufactured from a precursor containing molybdate, ferric and ammonium ions. The precursor is heated up to 150-250*C and thereafter admixed with water, shaped and dried. It may be activated by further heating. This catalyst which may contain minor amounts of additional metals may be used in the oxidation of methanol to formaldehyde.

Über die Struktur eines neuartigen Indolalkaloids, des Talbotins. 141. Mitteilung über Alkaloide [1]†

Abstract: From the leaves of the African Apocynacea Pleiocarpa talbotii Wernham a novel indole alkaloid, talbotine, C21H24N2O4, has been isolated. Talbotine (1) contains a secondary N(b)-atom and a cyclic hemiacetal group. Catalytic hydrogenation leads to 19, 20-dihydrotalbotine (6), hydrogenation in the presence of formaldehyde gives N(b)-methyl-19, 20-dihydrotalbotine (8). In the presence of sodium methoxide and methanol, 1 is converted into the lactone 12 and the methyl ester 13. In these reactions carbon 17 is lost as formic acid. These data, together with the analyses of the NMR. spectra of talbotine and its derivatives as well as the interpretation of the various types of the mass spectral fragmentation, lead to formula 1 for the alkaloid. Dehydrogenation of talbotine methyl ether (3) with palladium and maleic acid gives the s-carboline derivative 26. The N(b)-methiodide of the latter is converted into N(b)-methyl-talbotine methyl ether on reduction with sodium borohydride. From these data as well as from the analyses of NMR. and IR. spectra the complete relative stereochemistry of talbotine could be derived. Application of the Horeau method to the nitrogen atom b of the methyl ether 3 on the one hand and to the hydroxyl group on C17 in N(b)-methyl-19, 20-dihydrotalbotine (8) on the other hand gives consistent results and establishes S configuration of centre 15.

Low temperature methanol synthesis catalyst

Abstract: UNTIL RECENTLY LOW TEMPERATURE METHONAL SYNTHESIS CATALYSTS HAVE BEEN VIRTUALLY UNKNOW. A ZINC, COPPER AND CHROMIUM CATALYST HAS BEEN USED AS A LOW TEMPERATURE METHANOL SYNTHESIS CATALYST, BUT ALUMINA HAS BEEN DISCOUNTED AS HAVING NO PRACTICAL INTEREST AS AN INGREDIENT IN A METHANOL SYNTHESIS CATALYST. HOWEVER, UNDER CERTAIN CONDITIONS ALUMINA CAN BE USED TO ADVANTAGE IN SUCH CATALYSTS.

Process for the preparation of polyisobutenyl-substituted tetraethylenepentamine

Abstract: HYDROCARBYL POLYAMINES EXHIBIT IMPROVED DETERGENT/ DISPERSANT PROPERTIES AS ADDITIVES FOR LUBRICANTS AND FUEL OILS WHEN PREPARED BY EXTRACTING THE REACTION PRODUCT OF A POLYOLEFINIC CHLOROHYDROCARBON AND AN ALKYLENEPOLYAMINE WITH A LIQUID METHANOL OR ETHANOL SOLUTION.

Substitution at saturated carbon. Part IX. Free energies of transfer from methanol to aqueous methanol of tetra-alkyltins and the transition states in the bimolecular substitution of tetra-alklytins by mercuric chloride

Abstract: Standard free energies of transfer (on the molar scale) from methanol to various methanol–water mixtures have been determined for tetramethyl-, tetraethyl-, tetra-n-propyl-, and tetra-n-butyl-tin. When combined with similar previous data for mercuric chloride, and with the known free energies of activation for reaction (1), these free energies R4Sn + HgCl2→ RHgCl + R3SnCl (1) of transfer yield values of ΔGt°(Tr), the standard free energy of transfer from methanol to aqueous methanol of the corresponding transition states in reaction (1). It is shown that the reductions in the free energy of activation of reaction (1) observed when solvent methanol is replaced by aqueous methanol are due to very large increases in the standard free energy of the initial states on transfer from methanol to aqueous methanol.Standard entropies of transfer (on the molar scale) have also been calculated for the reactants and transition state in reaction (1; R = Et). The influence of various methanol–water mixtures on the value of ΔS‡ is shown to be due to a combination of initial-state and transition-state effects.

Conversion of methanol to formaldehyde

Abstract: Methanol is converted to formaldehyde in a two step vapor phase process. In the first step the methanol is partially converted to formaldehyde over a silver catalyst, and in the second step the remaining methanol is converted to formaldehyde over a bismuth molybdate- or bismuth phosphomolybdate-on-titania catalyst having the formula: Bi.sub.a P.sub.b Mo.sub.12 (Ti.sub.1.sub.-x Si.sub.x).sub.c O.sub.d Where a is equal to or greater than 4, b is 0 to 2, c is 6 to 80, d is 1.5a + 2.5b + 36 + 2c and x is 0 to 0.5.

Methanol process with recycle

Abstract: METHANOL IS MADE BY A PROCESS THAT INVOLVES FEEDING NATURAL GAS, STEAM, A RECYCLE STREAM AND OPTIONALLY CARBON DIOXIDE, TO A SINGLE BED TYPE REFORMER. THE RECYCLE STREAM IS THE UNCONVERTED GAS FROM THE METHANOL CONVERTER. THE REFORMER OUTPUT IS COOLED, COMPRESSED AND CONVERTED TO METHANOL IN A CONVERTER OPERATING AT 450750* F. AND 500 TO 1000 P.S.I.G. THE CONVERTER OUTPUT IS COOLED TO SEPARATE THE METHANOL FROM THE RECYCLE, I.E., THE UNCONVERTED GASES.

Catalytic oxidation of methanol over platinum

Abstract: The complete oxidation of methanol vapour over platinum has been studied using a micro-calorimetric technique. The results indicate two parallel reaction mechanisms, one which is inhibited by oxygen and one which is not. The derived activation energies indicate that the uninhibited reaction involves the rupture of an oxygen-metal bond in the rate-determining step.

Process for the manufacture of phosphonic acids and phosphonates having at least two phosphorus atoms

Abstract: A process for the manufacture of uniform, phosphonic compounds selected from the group consisting of phosphonic acids having at least two carbon atoms and at least two phosphorus atoms in their molecule and salts of said acids which consists essentially of the steps of acylating PCl3 with an excess of acylating agents selected from the group consisting of aliphatic and aromatic carboxylic acids having at least two carbon atoms in their molecules in the presence of water or acylating phosphorous acid with an excess of acid chlorides or acid anhydrides of the above acids at elevated temperatures up to the reaction boiling point, cooling the reaction mixture to a temperature above 30*C and below the boiling point of the alcohol added and adding thereto an alcohol selected from the group consisting of methanol, ethanol, propanol, butanol and pentanol, said alcohol being added in amounts of from 1.1 to 20 times the stoichiometrical amount, calculated on said excess of acylating agent, maintaining the reaction mixture in the said temperature range for a time sufficient to form volatile components, and recovering said phosphonic compounds free from impurities.