Industrial processes acetic anhydride

It should be emphasised that whereas the interaction of a sodium salt and an acid chloride is a convenient general laboratory method for preparing all classes of anhydrides, acetic anhydride is prepared on a large scale by other and cheaper methods. Industrial processes are based on reactions indicated by the equations ... 

Acetic Acid. Methanol carbonylation has become the process of choice for production of this staple of the organic chemical industry, which is used in the manufacture of acetate fibers, acetic anhydride [108-24-7] and terephthaUc acid, and for fermentation (see Acetic acid and derivatives). 

If acetic anhydride is employed in place of the sulphuric acid, only the sulphone is formed12,13 whilst if nitroethane or acetic acid are employed, no oxidation at sulphur occurs. A patent has been secured for the industrial oxidation of dimethyl sulphoxide to the sulphone with nitric acid14. This procedure yielded 84% of the sulphone in a continuous process which was prone to detonation at water concentrations below 14%. 

This process is carried out on an industrial scale in bubble columns [57]. Acetic acid and acetic anhydride are fed together with a recycle solution composed of acetic acid, acetyl chloride, monochloroacetic acid, dichloroacetic acid and hydrogen chloride. Under these conditions, acetic anhydride and hydrogen chloride give acetyl chloride spontaneously. 

Among the wide variety of organic reactions in which zeolites have been employed as catalysts, may be emphasized the transformations of aromatic hydrocarbons of importance in petrochemistry, and in the synthesis of intermediates for pharmaceutical or fragrance products.5 In particular, Friede 1-Crafts acylation and alkylation over zeolites have been widely used for the synthesis of fine chemicals.6 Insights into the mechanism of aromatic acylation over zeolites have been disclosed.7 The production of ethylbenzene from benzene and ethylene, catalyzed by HZSM-5 zeolite and developed by the Mobil-Badger Company, was the first commercialized industrial process for aromatic alkylation over zeolites.8 Other typical examples of zeolite-mediated Friedel-Crafts reactions are the regioselective formation of p-xylene by alkylation of toluene with methanol over HZSM-5,9 or the regioselective p-acylation of toluene with acetic anhydride over HBEA zeolites.10 In both transformations, the p-isomers are obtained in nearly quantitative yield. 

Used industrially as a chemical intermediate for organophosphorus insecticides, as a catalyst in the production of acetic anhydride by the ketene process and used in industry as a plasticizer, fire-retarding agent, antifoaming agent, and desensitizing agent for peroxides. 

The reaction of alkynes with nitric acid or mixed acid is generally not synthetically useful. An exception is the reaction of acetylene with mixed acid or fuming nitric acid which leads to the formation of tetranitromethane. A modification to this reaction uses a mixture of anhydrous nitric acid and mercuric nitrate to form trinitromethane (nitroform) from acetylene. Nitroform is produced industrially via this method in a continuous process in 74 % yield. " The reaction of ethylene with 95-100 % nitric acid is also reported to yield nitroform (and 2-nitroethanol). The nitration of ketene with fuming nitric acid is reported to yield tetranitromethane. Tetranitromethane is conveniently synthesized in the laboratory by leaving a mixture of fuming nitric acid and acetic anhydride to stand at room temperature for several days. ... 

Variations in the conditions used for the nitrolysis of hexamine have a profound effect on the nature and distribution of isolated products, including the ratio of RDX to HMX. It has been shown that lower reaction acidity and a reduction in the amount of ammonium nitrate used in the Bachmann process increases the amount of HMX formed at the expense of Bachmann and co-workers ° were able to tailor the conditions of hexamine nitrolysis to obtain an 82 % yield of a mixture containing 73 % HMX and 23 % RDX. Continued efforts to provide a method for the industrial synthesis of HMX led Castorina and co-workers to describe a procedure which produces a 90 % yield of a product containing 85 % HMX and 15 % RDX. This procedure conducts nitrolysis at a constant reaction temperature of 44 °C and treats hexamine, in the presence of a trace amount of paraformaldehyde, with a mixture of acetic acid, acetic anhydride, ammonium nitrate and nitric acid. Bratia and co-workers ° used a three stage aging process and a boron trifluoride catalyst to obtain a similar result. A procedure reported by Picard " uses formaldehyde as a catalyst and produces a 95 % yield of a product containing 90 % HMX and 10 % RDX. 

As in all large-scale industrial processes, the formation of the cellulose esters involves recovery of materials. Acetic anhydride is generally employed. After reaction, acetic acid and solvent are recovered. The recovered acetic acid is employed in the production of additional acetic anhydride. The recovered solvent is also reintroduced after treatment. 

Today acetic acid is produced mainly from methanol and carbon monoxide. This process, along with the Tennessee Eastman acetic anhydride plant using syn gas, are the current standards in the industry when considering new expansion regardless of the price of ethylene. The vinyl acetate process described here may achieve this stature if its commercial development is permitted to occur. 

Oxidation Oxidation of naphthalene by oxygen in the presence of vanadium pentoxide (V2O5) destroys one ring and yields phthalic anhydride (an important industrial process). However, oxidation in the presence of CrOs and acetic acid (AcOH) destroys the aromatic character of one ring and yields naphthoquinone (a diketo compound). 

Twenty-five years ago the domestic supply of acetic acid came from the distillation of wood. This, in the form of calcium acetate, was reacted with acetyl chloride to produce acetic anhydride to satisfy the wants of the infant cellulose acetate rayon industry. Shortly thereafter a better process came on the scene utilizing the reactants sodium acetate, sulfur dichloride, and chlorine. 

The carbonylation of methyl acetate to acetic anhydride is likely to become an industrial process in the near future 424,427 RhCl3-3H20 is typically used as catalyst precursor and an iodide promoter is used. A mechanistic study indicated that methyl iodide formed from the ester and HI is carbonylated as in acetic acid synthesis (Scheme 26). The resulting acyl, perhaps via reductive elimination of acetyl iodide, converts the acetic acid formed in the ester cleavage to acetic anhydride.428 430 [RhI(CO)(PPh3)2] also catalyzes the reaction though apparently more slowly than complex (95).430,431 The mechanism of this reaction is given in Scheme 27. 

Acetic Acid. Acetic acid production in the United States has increased by large numbers in the last half century, since the monomer has many uses such as to make polymers for chewing gum, to use as a comonomer in industrial and trade coatings and paint, and so on. In the 1930s, a three-step synthesis process from ethylene through acid hydrolysis to ethanol followed by catalytic dehydrogenation of acetaldehyde and then a direct liquid-phase oxidation to acetic acid and acetic anhydride as co-products was used to produce acetic acid... 

In recent years several commercial plants have been constructed for conversion of coal to synthesis gas for chemical manufacturing. These include the Eastman Chemical s acetic anhydride plant, the Ube (Japan) ammonia plant, the SAR (Germany) oxo chemicals plant, and several coal to ammonia plants in China (e.g., Weihe, Huainan, and Lunan). The Ube plant and the SAR plant have since converted to lower-cost opportunity fuels (petroleum coke and residues). The Eastman plant is still operating exclusively on coal. Feedstock changes at the other plants illustrate the vulnerability of coal conversion processes to a changing economic climate. The fact that the Eastman process remains competitive under changing conditions is due to a set of special circumstances that favor a coal-based process. The success of the Eastman chemicals from coal complex demonstrates that synthesis gas from coal is a viable feedstock for some industrial chemicals under certain conditions. 

In this chapter we discuss the mechanistic and other details of a few industrial carbonylation processes. These are carbonylation of methanol to acetic acid, methyl acetate to acetic anhydride, propyne to methyl methacrylate, and benzyl chloride to phenyl acetic acid. Both Monsanto and BASF manufacture acetic acid by methanol carbonylation, Reaction 4.1. The BASF process is older than the Monsanto process. The catalysts and the reaction conditions for the two processes are also different and are compared in the next section. Carbonylation of methyl acetate to acetic anhydride, according to reaction 4.2, is a successful industrial process that has been developed by Eastman Kodak. The carbonylation of propyne (methyl acetylene) in methanol to give methyl methacrylate has recently been commercialized by Shell. The Montedison carbonylation process for the manufacture of phenyl acetic acid from benzyl chloride is noteworthy for the clever combination of phase-transfer and organometallic catalyses. Hoechst has recently reported a novel carbonylation process for the drug ibuprofen. 

Summary DNAT, l,l -dinitro-3,3 -azo-1,2,4-triazole, is prepared by oxidizing 3-amino-1,2,4-triazole to 3,3 -azo-1,2,4-triazole with potassium permanganate, and then treating that intermediate with nitric acid in the presence of acetic anhydride. The precipitated product is then recovered by filtration, and then recrystallized from acetone. Commercial Industrial note Part or parts of this laboratory process may be protected by international, and/or commercial/industrial processes. Before using... 

Summary beta-HMX can be prepared by reacting hexamine with ammonium nitrate and nitric acid in the presence of excess glacial acetic acid and acetic anhydride. The rate of additions is crucial to ensure proper HMX formation. After the reaction is complete, the alpha-HMX is refluxed with water to ensure quality and purification. The resulting water insoluble product is then filtered-off, and then recrystallized from acetone to produce excellent crystals of beta-HMX. Commercial Industrial note For related, or similar information, see Serial No. 696,888, November 15th, 1957, by The United States Army, to Jean P. Picard, Morristown, NJ. Part or parts of this laboratory process may be protected by international, and/or commercial/industrial processes. Before using this process to legally manufacture the mentioned explosive, with intent to sell, consult any protected commercial or industrial processes related to, similar to, or additional to, the process discussed in this procedure. This process may be used to legally prepare the mentioned explosive for laboratory, educational, or research purposes. 

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