Subject alkalinity

A special application of the Japp-Klingemann/Eischer sequence is in the preparation of tryptamines from piperidone-3-carboxylate salts, a method which was originally developed by Abramovitch and Shapiro[2]. When the piperidone is subjected to Japp-Klingemann coupling under mildly alkaline conditions decarboxylation occurs and a 3-hydrazonopiperidin-2-one is isolated. Fischer cyclization then gives 1-oxotetrahydro-p-carbolines which can be hydrolysed and decarboxylated to afford the desired tryptamine. 

Chemical Properties. Anhydrous sodium dithionite is combustible and can decompose exothermically if subjected to moisture. Sulfur dioxide is given off violentiy if the dry salt is heated above 190°C. At room temperature, in the absence of oxygen, alkaline (pH 9—12) aqueous solutions of dithionite decompose slowly over a matter of days. Increased temperature dramatically increases the decomposition rate. A representation of the decomposition chemistry is as follows ... 

Hydrolysis. The hydrolysis of dialkyl and monoalkyl sulfates is a process of considerable iaterest commercially. Successful alkylation ia water requires that the fast reaction of the first alkyl group with water and base be minimised. The very slow reaction of the second alkyl group results ia poor utilisation of the alkyl group and gives an iacreased organic load to a waste-disposal system. Data have accumulated siace 1907 on hydrolysis ia water under acid, neutral, and alkaline conditions, and best conditions and good values for rates have been reported and the subject reviewed (41—50). 

Sa.tura.tion Index. Materials of constmction used in pools are subject to the corrosive effects of water, eg, iron and copper equipment can corrode whereas concrete and plaster can undergo dissolution, ie, etching. The corrosion rate of metallic surfaces has been shown to be a function of the concentrations of Cl ,, dissolved O2, alkalinity, and Ca hardness as well as buffer intensity, time, and the calcium carbonate saturation index (35). 

Drinking water suppHed to carbonated soft drink manufacturing faciUties from private or municipal sources must comply with all regulatory requirements. Treated water must meet all U.S. Environmental Protection Agency primary maximum contaminant levels and may also be subject to additional state requirements. Treated water is routinely analyzed for taste, odor, appearance, chlorine, alkalinity, iron, pH, total dissolved soHds, hardness, and microbiological contamination. 

Manufacture. A limited, amount of natural cinnamyl alcohol is produced by the alkaline hydrolysis of the cinnamyl cinnamate present in Styrax Oil. Thus treatment of the essential oil with alcohoHc potassium hydroxide Hberates cinnamyl alcohol of reasonable purity which is then subjected to distillation. This product is sometimes preferred in fine fragrance perfumery because it contains trace impurities that have a rounding effect in finished formulations. 

A reactive dye—cellulose bond is subject to some slight hydrolysis during washing under alkaline conditions. 

Compounds such as hydrogen sulfide and cyanides are the most common metal surface poisoners occurring in process units subject to aqueous-phase hydrogen attack. In many process units, these compounds can be effectively eliminated and hydrogen diffusion stopped by adding ammonium polysulfides and oxygen to the process streams which converts the compounds to polysulfides and thiocyanates, provided the pH is kept on the alkaline side. 

In a process said to be operated in Britain castor oil is subjected to alkaline fusion under critically controlled conditions to produce a mixture of methyl hexyl ketone and w-hydroxydecanoic acid. Interaction of these two materials at higher... 

When the l<, 2( -d2-labeled product (129) is subjected to alkaline equilibration to back exchange the 2i -label (for experimental conditions see section IT-B), the crystalline l< -di-4,4-dimethyl-5a-androstan-3-one (130) exhibits 6% do and 94% d isotopic composition. ... 

The thiono derivatives of tetrahydro-1,3-oxazine became a subject matter of some interest since Kjaer and Jensen discovered that products of enzymatic hydrolysis of Malcolma maritima contain 6-methyl- and 6,6-dimethyl-2-thionotetrahydro-l,3-oxazine (26). The authors proved the identity of these compounds with the products of cyclization of 3-hydroxypropyl-isothiocyanate in an alkaline medium. 

I have found that a mixture of citral and acetone, if it is subjected, in the presence of water, for a suffieiently long time to the action of hydrates of alkaline earths or of hydrates of alkali metals, or of other alkaline agents, is eondensed to a ketone of the formula CjjH pO. This substanee, which I term Pseudo-ionone," may be produced lor instance in shaking together for several days equal parts of citral and acetone with a solution of hydrate of barium, and in dissolving the products of this reaction in ether. 

The process for the production of the pseudo-ionone referred to in the first claim, consisting in the subjection of a mixture of citral and acetone to the action of an alkaline agent, and in purifying the product of this reaction, extracted by means of ether, by fractional distillation, substantially as described. 

After cooling, the solution was diluted with 1.5 liters of water and subjected to three extractions with ether. The amine was extracted from the ethereal solution with 2 N HCI and liberated therefrom by the addition of solid NaOH (while cooling). The alkaline solution was extracted with ether and the ethereal solution was dried with soiid NaOH. Distii-lation resulted in 10.6 grams (70% of the theory) of 1-aminoadamantane which, after sublimation, melted at 180° to 192°C (seal capillary). It is converted to the hydrochloride. 

A solution containing 741 g (5.0 mols) of 1-phenyl-2-propylidenylhydrazine, 300 g (5.0 mols) of glacial acetic acid and 900 cc of absolute ethanol was subjected to hydrogenation at 1,875 psi of hydrogen in the presence of 10 gof platinum oxide catalyst and at a temperature of 30°C to 50°C (variation due to exothermic reaction). The catalyst was removed by filtration and the solvent and acetic acid were distilled. The residue was taken up In water and made strongly alkaline by the addition of solid potassium hydroxide. The alkaline mixture was extracted with ether and the ether extracts dried with potassium carbonate. The product was collected by fractional distillation, BP B5°C (0.30 mm) yield 512 g (68%). 

Nickel is usually alloyed with elements including copper, chromium, molybdenum and then for strengthening and to improve corrosion resistance for specific applications. Nickel-copper alloys (and copper-nickel alloys see Section 53.5.4) are widely used for handling water. Pumps and valve bodies for fresh water, seawater and mildly acidic alkaline conditions are made from cast Ni-30% Cu type alloys. The wrought material is used for shafts and stems. In seawater contaminated with sulfide, these alloys are subject to pitting and corrosion fatigue. Ammonia contamination creates corrosion problems as for commercially pure nickel. 

Cast iron behaves in a manner similar to steel at alkaline pH values but at low pH values it is subject to graphitisation. 

Salts giving an alkaline reaction may be corrosive to the irons, and while neutral solutions can be handled safely there is usually little point in using high-silicon irons for these relatively innocuous solutions. The irons are useful in handling acidic solutions, subject to the restrictions already referred to regarding the halide, sulphite and phosphate ions. 

Wood is particularly valuable for many conditions which are corrosive to common metals (e.g. acids and external exposure), and for contact with foodstuffs and beverages. It is not subject to corrosion in the electrochemical sense of the term applied to metals, but in saline conditions it can be attacked by the products of metal corrosion (alkali and iron salts) where poor technology or unsuitable wood species are used. Although wood is attacked by both extremely alkaline and acid conditions, particularly those which are oxidising, it can be employed over a wider pH range than most other materials. 

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