Excess Hydroxide Research Articles

Synthesis of 2-mercaptobenzthiazole derivatives

The reactions of 2, 3-dihydrothiazolo- (I) and 2, 3-dihydrothiazino-1, 3-[2, 3-b]benzthiazolium chlorides (II) with water, aqueous sodium hydroxide, aqueous alcoholic ammonia, and hydrazine hydrate are investigated. Excess alcoholic potassium hydroxide cleaves I and II to o-(Ω-mercaptoalkylamino) thiophenols, condensation of which with acetyl chloride followed by treatment of the reaction products with potassium iodide gives 2-methyl-3-(Ω-mercaptoalkyl)benzthiazolium iodides. A series of dyes is prepared from these compounds.

Electrochemical oxidation of oxalate ion in dimethylsulfoxide at a gold electrode

The electrochemical oxidation of oxalate ion in dimethylsulfoxide at a gold electrode has been studied by chronopotentiometry and cyclic voltammetry. The final oxidation product is carbon dioxide but an unstable intermediate is formed during the oxidation process. In the absence of excess hydroxide ion, oxalate ion is partly hydrolyzed to acid oxalate ion which is oxidized to carbon dioxide and hydrogen ions. Oxidation mechanisms are proposed that are consistent with the data.

Electrochemical oxidation of oxalate ion in dimethylsulfoxide at a gold electrode

The electrochemical oxidation of oxalate ion in dimethylsulfoxide at a gold electrode has been studied by chronopotentiometry and cyclic voltammetry. The final oxidation product is carbon dioxide but an unstable intermediate is formed during the oxidation process. In the absence of excess hydroxide ion, oxalate ion is partly hydrolyzed to acid oxalate ion which is oxidized to carbon dioxide and hydrogen ions. Oxidation mechanisms are proposed that are consistent with the data.

On the mechanism of the Guerbet reaction

The reaction between an alcohol and an alkanolate in presence of excess potassium hydroxide (the Guerbert reaction) has been studied, mainly with benzyl alcohol and potassium lactate as reactants, α-hydroxy-γ-phenylbutyric acid being formed in the reaction. 1. It has been confirmed that the reaction proceeds in a series of consecutive steps: 1.1. A dehydrogenation of the hydroxyl compounds to carbonyl compounds. 1.2. Aldol condensation between the carbonyl compounds, followed by elimination of water 1.3. Hydrogenation of the α,β-unsaturated ketone formed, the original hydroxyl compounds reacting as hydrogen donors, thus initiating a chain reaction. 1.4. A disproportionation of aldehyde to alcohol and acid under the influence of potassium hydroxide, this reaction breaking the chain reaction mentioned under (c). 2. The reaction may take place without the addition of a catalyst but it is strongly catalysed by hydrogen-transferring catalysts (Raney-Ni, Pd). 3. At relatively low temperatures (130–140°) the dehydrogenating process is the rate determining process. 4. At higher temperatures (160–180°) the reaction steps (b) or (c) are rate determining, most likely (b), as, if (c) were rate determining, an accumulation of aldol would take place, leading to a polycondensation, and no tendency of polycondensation has been observed. 5. At still higher temperatures other reactions, resulting in the formation of carbon monoxide and other destruction products, become dominating. 6. At the temperature at which the reaction usually has been studied (160–180°) the composition of the reaction mixture is determined by the ratio between the rates of step (b) and step (d). 7. Addition of the α,β-unsaturated ketone presumed as intermediate to the reaction mixture allows the reaction to proceed at considerably lower temperature than without such addition, thus improving the yield as the temperature coefficient of step (d) is higher than that of (b) and (c).

THE MEASUREMENT OF GLYCEROL IN THE PRESENCE OF CITRATE.

A method for determining glycerol in citrated blood is described. It was found that citrate ions produce interfering turbidity when the procedure recommended by Bailey is applied to glycerol‐citrate‐blood mixtures. The addition of absolute alcohol during deproteinization results in the precipitation of citrates and eliminates the need for zinc sulfate and its subsequent removal by the addition of excess barium hydroxide. The average recovery of glycerol added to blood‐citrate mixtures is 99 per cent.

Free radical addition reactions—II : The reaction of trichloromethanesulphonyl chloride with styrene, and chemistry of the adducts

Trichloromethanesulphonyl chloride reacts with styrene to give 1-phenyl-1,3,3,3-tetrachloropropane and 1,3-diphenyl-1,5,5,5-tetrachloropentane, together with sulphur dioxide. Hydrolysis of 1-phenyl-1,3,3,3-tetrachloropropane to cinnamic acid (90% yield) is catalysed by ferric chloride, and occurs under conditions that do not markedly affect 1,1,1,3-tetrachlorooctane. Acetolysis of 1-phenyl-1,3,3,3-tetrachloropropane gives largely 1-phenyl-3,3,3-trichloropropyl acetate; reduction of this compound with lithium aluminium hydride gives 1-phenylpropanol, confirming the position of the acetate group. A mechanism is proposed to account for the formation of 1,1-dimethoxy-1-phenylprop-2-yne in the reaction of 1-phenyl-1,3,3,3-tetrachloropropane with excess methanolic potassium hydroxide. Reduction of 1,3-diphenyl-1,5,5,5-tetrachloropentane with lithium aluminium hydride provides a synthesis of 1,3-diphenylpentane

Structure of the copper-mannite complex determined in solution by A.C. polarography

It was found that marmite-copper hydroxide complex dissolves in excess alkali hydroxide as a complex such as mannite-2[Cu(OH) 3] −. The polarographic analysis of copper ion is more accurate in the presence of mannite than the more conventional determination in the absence of mannite.

The formation of magnesium hydroxide

1. The system MgA2 + NaOH + H2O (25°), where A=Cl−, NO3−1, or 1/2SO 4 2− , have been examined by means of liquid and solid phase analysis, by the determination of the apparent precipitate volume, and by following pH changes. The only product formed in these systems was magnesium hydroxide; no basic or other type complexes were found. 2. Magnesium hydroxide precipitated in solutions where the initial ratio of NaOH:MgA2=4, is not exceeded, does not carry along any excess hydroxide ion, and therefore magnesium can be determined quantitatively (gravimetrically, volumetrically, and potentiometrically) by a precipitation in excess alkali. 3. From the measurements of precipitate volume in the investigated systems one can decide on the optimum conditions for producing the most compact magnesium hydroxide which may be of some technological value and of use in analytical chemistry.

Small-Ring Compounds. XVII. 2-Hydroxy-3-phenyl-2-cyclobutenone and Related Substances1

1,1,2-Trifluoro-2-chloro-3-phenylcyclobutane (I ) undergoes dehydrohalogenation with one mole of ethanolic potassium hydroxide and is converted to 1,1,2-trifluoro-3-phenyl-2-cyclobutene (II). With excess ethanolic potassium hydroxide, I, II or 1,1,2,2-tetrafluoro-3-phenylcyclobutane (IV) yield 1,1-difluoro-2-ethoxy-3-phenyl-2-cyclobutene (III). Hydrolysis of III in 92% sulfuric acid affords 2-ethoxy-3-phenyl-2-cyclobutenone (V) which is rather more stable toward acid hydrolysis than ordinary vinyl ethers. Treatment of I with excess potassium-butoxide in t-butyl alcohol yields 1.1-difluoro-2-t-butoxy-3-phenyl-2-cyclobutene (VI) which, on acid hydrolysis, gives 2-hydroxy-3-phenyl-2-cyclobutenone (VII). The pK_A of VII was found to be 3-4 units lower than the pK_A's of 2-hydroxy-2-cyclopentenone and 2-hydroxy-2-cyclohexenone.

The determination of carbon dioxide in coal

AbstractIn the present British Standard method for the determination of carbon dioxide in coals, the carbon dioxide evolved by reaction of the coal with dilute hydrochloric acid or phosphoric acid is absorbed in barium hydroxide, and the excess barium hydroxide is titrated with hydrochloric acid. In Fuel Research Survey Paper No. 44, a method is described in which the carbon dioxide liberated is absorbed in soda‐lime and determined gravimetically. In this paper a third method based on the pressometric principle is described. The amount of carbon dioxide is determined by measuring the pressure developed in an apparatus of constant volume, the pressure and volume relationship having previously been determined using a known amount of sodium carbonate.

MICRO METHOD OF DETERMINING CARBON IN PORCELAIN AND THE TRANSLUCENCY OF PORCELAIN

The carbon content in porcelain was determined by the application of the micromethod proposed by M. H. Kalina and T. L. Joseph (Blast Furnace and Steel Plant, 1939, 345-351) for carbon in steel. Specimens of porcelain were powdered to pass 130 mesh per inch and fused with red lead in a platinum boat in a current of oxygen. The carbon dioxide evolved was absorbed with barium hydroxide solution. Excess barium hydroxide was titrated back.As a measure of translucency, the extinction coefficient of porcelain thin plate was measured by a Hartmann microphotometer.A few examples of the measured results are shown in the following.Specimens were taken out from several parts of a working tunnel kiln. The water absorption and the carbon content of these specimens were measured. The results are shown in Fig. 3 (I&II). It was shown that the carbon content of specimens fired the range of 900° to 1000°C was about 0.03%, and it was reduced to about 0.01% before the beginning of the vitrification.

The Use of Salicylic Acid as a Fixative

The following salicylic acid-containing fixatives are useful for cytological studies in plants. The first, here designated HFC, is recommended for studies on somatic mitosis and chromosome individuality. The second, denoted HFP, is recommended for studies on plastids.HFC is made up in two solutions. Sol. A: 100 cc. sat. aq. sol. salicylic acid, slight excess copper hydroxide, 20 cc. formaldehyde, 30 cc. normal ortho-phosphoric acid, 200 cc. water, 1 g. saponin; pH 1.8 to 1.9. Fix in Sol. A 15 to 30 minutes in partial vacuum of 35 cms. Then add Sol. B: 1% aq. chromic acid in equal parts. Continue fixation for period of 18 to 24 hours.HFP is also made up in two solutions which are used in equal parts. Sol. A: 100 cc. sat. aq. sol. salicylic acid, slight excess copper hydroxide, 10 cc. normal ortho-phosphoric acid, 1/2 g. saponin. Sol. B: 187.5 cc. 1% aq. chromic acid, 50 cc. 2% osmic acid. Fixation technic as HFC.Dehydrate and infiltrate with paraffin after Zirkle. Stain with crystal-violet-iodine.

STUDIES UPON THE COPPER FUNGICIDES

SUMMARY The initial product of the interaction ol cupric sulphate and calcium hydroxide solutions, at ordinary temperatures, is the 4CuO. S03 basic sulphate. With amounts of calcium hydroxide in excess of 0–75 equivalent, the 4CuO. S03 salt is slowly decomposed with elimination of the sulphate radicle and the formation of a blue hydrated cupric oxide or cupric hydroxide, a product called, for convenience, the hydroxide. The cupric hydroxide formed retains, by adsorption, part of the sulphate radicle. Direct evidence by analysis of the precipitate, which might be considered to indicate the formation of a basic copper‐calcium complex, is therefore unreliable. In the analogous interaction of calcium hydroxide with cupric chloride, the formation of cupric hydroxide in the presence of amounts of calcium hydroxide in excess of 0–75 equivalent, is indicated by the dehydration of the precipitate to form nigger brown hydrated cupric oxide, and by the definite point of inflection on the hydrogen‐ion concentration curve which corresponds to equimolecular amounts of calcium hydroxide and cupric chloride. The hydrogen‐ion concentration curve for the cupric sulphate‐calcium hydroxide reaction shows that permanent alkalinity is not‐reached until equimolecular amounts of calcium hydroxide have been added. The cupric hydroxide, formed from the 4CuO.SO3 basic sulphate by the action of calcium hydroxide, is stabilised by adsorbed sulphate ions. If the adsorbed sulphate and excess calcium hydroxide be removed by continued washing with carbon dioxide‐free water, the Bordeaux mixture precipitate undergoes dehydration to form the nigger brown hydrated cupric oxide. Dehydration of the Bordeaux mixture precipitate when sprayed upon foliage, is therefore prevented by some chemical or physical change of the precipitate which occurs on drying. Dehydration is not prevented by physical changes which occur on drying. Carbon dioxide is a factor in the process whereby dehydration is prevented. It is suggested that the formation in situ of the protective copper‐containing deposit by the action, primarily, of carbon dioxide, accounts for the excellent adhesive properties of the Bordeaux mixture precipitate; that inertness towards the chemical changes which occur after spraying may be the cause of failure of some Bordeaux substitutes; that these changes may profoundly affect the value of sedimentation tests as criteria for the fungicidal efficiency of various Bordeaux mixtures.