Acid water products

HCOOCHjCHj. Colourless liquid with the odour of peach-kernels b.p. 54 C, Prepared by boiling ethanol and methanoic acid in the presence of a little sulphuric acid the product is diluted with water and the insoluble ester separated and distilled. Used as a fumigant and larvicide for dried fruits, tobacco and foodstuffs. It is also used in the synthesis of aldehydes. 

In a widely used industnal process the mixture of ethylene and propene that is obtained by dehydrogenation of natural gas is passed into concentrated sulfunc acid Water is added and the solution IS heated to hydrolyze the alkyl hydrogen sulfate The product is almost exclusively a sin gle alcohol Is this alcohol ethanol 1 propanol or 2 propanoH Why is this particular one formed almost exclusively" ... 

Single-reaction-step processes have been studied. However, higher selectivity is possible by optimizing catalyst composition and reaction conditions for each of these two steps (40,41). This more efficient utilization of raw material has led to two separate oxidation stages in all commercial faciUties. A two-step continuous process without isolation of the intermediate acrolein was first described by the Toyo Soda Company (42). A mixture of propylene, air, and steam is converted to acrolein in the first reactor. The effluent from the first reactor is then passed directiy to the second reactor where the acrolein is oxidized to acryUc acid. The products are absorbed in water to give about 30—60% aqueous acryUc acid in about 80—85% yield based on propylene. 

The Hquid reacts violentiy with water, releasing HCl and other gases ia sufficient amounts to cause sudden mpture of closed or inadequately vented containers. The acid reaction products can react with metals to generate hydrogen, which is flammable and explosive. The oral LD q in rats is 380 mg/kg the inhalation LC q for rats is 48 ppm/4 h, and for guinea pigs, 53 ppm/4 h (35). 

Yields are best in the case of aromatic metallic reagents. Use of aUphatic reagents favors low molecular weight products. Products often are recovered by water addition, followed by separation and distillation of the organic layer. Such procedures inevitably lead to acidic by-products when there is incomplete replacement of the halogens on phosphoms. A modification of the Wurt2 reaction sometimes is used. 

Bisamides. Methylenebisamides are prepared by the reaction of the primary fatty amide and formaldehyde in the presence of an acid catalyst. AijAT-Methylenebisoleamide has been made via this route without the use of refluxing solvent (55). Polymethylenebisamides can be made from fatty acid, esters, or acid haUdes with diamines while producing water, alcohol, or mineral acid by-products. Eatty acids and diamines, typically ethylenediamine, have been condensed in the presence of NaBH and NaH2P02 to yield bisamides (56). When stearic acid, ethylenediamine, and methyl acetate react for 6 h at... 

Oxidation. Citric acid is easily oxidized by a variety of oxidizing agents such as peroxides, hypochlorite, persulfate, permanganate, periodate, hypobromite, chromate, manganese dioxide, and nitric acid. The products of oxidation are usually acetonedicarboxyhc acid (5), oxaUc acid (6), carbon dioxide, and water, depending on the conditions used (5). 

The mother liquor is separated from the product and returned to the tower. Copper(II) oxychloride is iasoluble ia water, but dissolves readily ia mineral acids or warm acetic acid. The product dissolves ia ammonia and alkah cyanide solution upon the formation of coordination complexes. 

Coppet(I) oxide is stable in dry air, but reacts with oxygen to form coppet(II) oxide in moist air. CU2O is insoluble in water, but dissolves in ammonia or hydrochloric acid. The product disproportionates to copper metal and coppet(II) in dilute sulfuric or nitric acid. 

The mixed oxidation products are fed to a stiU where the pelargonic and other low boiling acids are removed as overhead while the heavy material, esters and dimer acids, are removed as residue. The side-stream contains predominately azelaic acid along with minor amounts of other dibasic acids and palmitic and stearic acids. The side-stream is then washed with hot water that dissolves the azelaic acid, and separation can then be made from the water-insoluble acids, palmitic and stearic acids. Water is removed from the aqueous solution by evaporators or through crystallization (44,45). 

Completion of Esterification. Because the esterification of an alcohol and an organic acid involves a reversible equiUbrium, these reactions usually do not go to completion. Conversions approaching 100% can often be achieved by removing one of the products formed, either the ester or the water, provided the esterification reaction is equiUbrium limited and not rate limited. A variety of distillation methods can be appHed to afford ester and water product removal from the esterification reaction (see Distillation). Other methods such as reactive extraction and reverse osmosis can be used to remove the esterification products to maximize the reaction conversion (38). In general, esterifications are divided into three broad classes, depending on the volatility of the esters ... 

The product may be recrystallized from 1 2 acetic acid-water (about 8 ml./g.), but this process effects little improvement in melting point or color, even when activated carbon is used. 

A solution of the crude cyanohydrin (94a ca. 1 g) in pyridine (15 ml) and acetic anhydride (15 ml) is allowed to stand at room temperature for 52 hr. The solvents are evaporated under reduced pressure below 60°. The residue is dissolved in ether, and the ether solution is washed successively with 5 % hydrochloric acid, water and saturated salt solution. The solvent is evaporated under reduced pressure to give a crystalline residue. Recrystallization of the crude product from cyclohexane-acetone gives 3-methoxy-17a-cyano-estra-l,3,5(10)-trien-17i5-ol acetate (94b 0.9 g), mp 130-132°, as large prisms. 

Sorm" " found that when cholesterol acetate (67) is oxidized by chromic acid in acetic acid-water at 55°, crystalline keto seco-acid (69) is obtained in 25-30 % yield from the mother liquors after removal of successive crops of 7-ketocholesterol acetate (68). Reaction of keto acid (69) with benzoyl chloride in pyridine gives a dehydration product, shown" to be the )5-lactone... 

Catalyst A mixture of 5.26 g of rhodium chloride trihydrate, 0.34 g of palladium chloride, 18 g of carbon (Darco G-60), and 200 ml of water is rapidly stirred and heated to 80°. A solution of lithium hydroxide hydrate (2.7 g) in 10 ml of water is added in one portion and the heating discontinued. Stirring is continued overnight, after which the mixture is filtered and washed with 100 ml of 0.5 % aqueous acetic acid. The product is dried in a vacuum oven at 65°. About 20 g of the catalyst is thus obtained. 

The original scientific account of the preparation of this body stated that mcfa-isohutyl toluene was heated on a water-bath for twenty-four hours, with five times its weight of a mixture of sulphuric and nitric acids. The product was subjected to a repetition of the same treatment, so as to convert it into trinitro-butyl toluene, which crystallises from alcohol in white needles melting at 96° to 97°. It is insoluble in water, but soluble in organic solvents. Even in very dilute solutions this compound has a. 

Brass water fittings give no trouble except that dezincification may occur in acid waters or waters of high chloride content, especially when hot. This dezincification has three effects. Firstly, the replacement of brass by porous copper may extend right through the wall of the fitting and permit water to seep through. Secondly, the zinc which is dissolved out of the brass may form very voluminous hard corrosion products and eventually block the waterway —this is often the case in hot soft waters. Thirdly, and often the most important, the mechanical properties of the brass may deteriorate. For instance, a dezincified screwed union will break off when an attempt is made to unscrew it and a dezincified tap or ball-valve seat is readily eroded by the water. 

However, they can also be prepared by metal exchange from alkali-metal phthalocyanines. If proton donors like hydrochloric acid, water or methanol are added to the reaction mixture of a freshly prepared alkali-metal phthalocyanine, metal-free phthalocyanines (PcH2) are formed (see Section 2.1.4.1,). If, on the other hand, the appropriate metal salt is added to a solution of an alkali-metal phthalocyanine, the product is the metalated compound (PcM) (see Section 2.1.6.). 

This material is acetylated with 35 ml. of pyridine and 35 ml. of acetic anhydride for 6 hours at room temperature. The mixture is then poured onto 250 g. of ice and extracted with five 75-ml. portions of ether. The combined ether extracts are washed successively with three 10-ml. portions each of saturated aqueous sodium bicarbonate and water and then dried over magnesium sulfate. It is important not to use strong acids such as hydrochloric or sulfuric acid to remove pyridine as was done in Part A, since they can destroy the acid-sensitive product. 

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