Industrial alcohol production, ester hydrolysis

Beside the MMFO mediated (phase I) reactions there are a few other major reactions that are worthy of note. The two major ones involve ester hydrolysis and alcohol and aldehyde dehydrogenases. All mammalian species have an extensive ability to hydrolyze the ester bond. The products of the reactions then can go on to be further metabolized. In the pharmaceutical industry, this property has been utilized to synthesize prodrugs that is, chemicals that have desirable pharmaceutical properties (generally increased water solubility) that are not converted to their active moiety until hydrolyzed in the body. 

In this framework, the class of lipases is made up of enzymes largely employed in pharmaceutical productions, whose product is specific enantiomeric forms of organic compounds (alcohols, adds, esters, amines). The enantioselective hydrolysis of racemic esters and simultaneous separation of the corresponding optically pure (5)-add as pure isomer is of considerable interest to the pharmaceutical industry as a route to non-steroidal anti-inflammatory drugs. In this field, studies have been devoted to the feasibility analysis of MBRs to produce (5)-ibuprofen esters and acids. Studies related to the modeling of the lipase-catalyzed hydrolysis of (S)-ibuprofen acid in MBRs show the feasibility of EMRs for the stereo-selective production of (S )-ibuprofen add indeed, the model indicates a high effidency of the EMR in the kinetic resolution of racemic solutions. ... 

Prepared generally by ester interchange from polyvinylacelate (ethanoate) using methanol and base also formed by hydrolysis of the acetate by NaOH and water. The properties of the poly(vinyl alcohol) depend upon the structure of the original polyvinyl acetate. Forms copolymers. Used as a size in the textile industry, in aqueous adhesives, in the production of polyvinyl acetates (e.g. butynal) for safety glasses. U.S. production 1980... 

The industrial process for preparing the reagent usually permits a little hydrolysis to occur, and the product may contain a little free calcium hydroxide or basic chloride. It cannot therefore be employed for drying acids or acidic liquids. Calcium chloride combines with alcohols, phenols, amines, amino-acids, amides, ketones, and some aldehydes and esters, and thus cannot be used with these classes of compounds. 

Benzyl Alcohol Phenylmethanol or Hydroxytol-uene (called l -Oxy-T-methyl-benzol and benzyl chloride with Na or K carbonate in soln or by other methods. There are two commercial products technical grade and "FFC (free from chlorine) grade(Ref 3). Toxicity and fire hazard are discussed in Ref 5. It is used extensively in many branches of the chem industries, such as, for the manuf of esters(acetic, benzoic, sebacic, etc), as a solvent for cellulose esters ethers, etc. During WW I, it was used in a "dope for airplane fabrics... 

Secondary alcohols (C1Q—C14) for surfactant intermediates are produced by hydrolysis of secondary alkyl borate or boroxine esters formed when paraffin hydrocarbons are air-oxidized in the presence of boric acid [10043-35-3] (19,20). Union Carbide Corporation operated a plant in the United States from 1964 until 1977. A plant built by Nippon Shokubai (Japan Catalytic Chemical) in 1972 in Kawasaki, Japan was expanded to 30,000 t/yr capacity in 1980 (20). The process has been operated industrially in the USSR since 1959 (21). Also, predominantly primary alcohols are produced in large volumes in the USSR by reduction of fatty acids, or their methyl esters, from permanganate-catalyzed air oxidation of paraffin hydrocarbons (22). The paraffin oxidation is carried out in the temperature range 150—180°C at a paraffin conversion generally below 20% to a mixture of trialkyl borate, (RO)3B, and trialkyl boroxine, (ROBO)3. Unconverted paraffin is separated from the product mixture by flash distillation. After hydrolysis of residual borate esters, the boric acid is recovered for recycle and the alcohols are purified by washing and distillation (19,20). 

Oleochemical Route. Oleochemicals. Oleochemicals are chemicals derived from oils or fats. They are analogous to petrochemicals, which are chemicals derived from petroleum. The hydrolysis or alcoholysis of oils or fats form the basis of the oleochemical industry. The hydrolysis of the triglycerides composing oils and fats produces fatty acids and glycerol. If oils or fats are made to react with an alcohol instead of with water, the process is alcoholysis, and the products are fatty acid esters and glycerol. 

Chlorination of toluene under radical conditions (either through the use of an initiator or by photolysis) gives a mixture of mono-, di- and trichlorotoluene. In practice in the perfumery industry, the reaction is run with an excess of toluene present, which means that benzyl chloride is the major product. A little benzal chloride is produced and can be separated and hydrolysed to give benzaldehyde. The major use of benzyl chloride is in the production of benzyl alcohol and its esters. The alcohol is produced by hydrolysis of the chloride. The esters can be prepared by esterification of the alcohol, but it is better economically to prepare... 

The chemical properties of PVAc are those of an aliphatic ester. Thus, acidic or basic hydrolysis produces poly(vinyl alcohol) and acetic acid or the acetate of the basic cation. Industrially, poly(vinyl alcohol) is produced by a base-catalyzed ester interchange with methanol, where methyl acetate forms in addition to the pol5mieric product. The chemical properties of PVAc can be modified by copolymerization. When a comonomer having a carboxylic acid group or a sulfuric acid group is used, the copolymer becomes soluble in dilute aqueous alkah or... 

The reaction of triacylglycerols with alcohol is called alcoholysis. It can be catalysed by acids (sulfuric acid or 4-toluenesulfonic acid), and then an interesterification reaction, which is a parallel reaction to esterification of free fatty acids occurring in the fat. Alcoholysis is kinetically similar to esterification. The base catalysed reaction employs methoxides, hydroxides and carbonates of alkali metals. The most commonly used catalysts are sodium methoxide, sodium hydroxide or potassium hydroxide. Industrially produced alcoholysis products are methyl, ethyl or propyl esters (Figure 3.82) of fatty acids. Analogous to hydrolysis, mixing of fat (oil) with alcohol gives a two-phase system... 

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