Acetonitrile, manufacture

Although no ethane ammoxidation process is as yet commercial, advances in the catalyst technology may make it an economic alternative for acetonitrile manufacture in the near future. Thus, virtually all the acetonitrile produced commercially comes from the ammoxidation of propylene. 

Amm oxida tion, a vapor-phase reaction of hydrocarbon with ammonia and oxygen (air) (eq. 2), can be used to produce hydrogen cyanide (HCN), acrylonitrile, acetonitrile (as a by-product of acrylonitrile manufacture), methacrylonitrile, hen onitrile, and toluinitnles from methane, propylene, butylene, toluene, and xylenes, respectively (4). 

Most, if not all, of the acetonitrile that was produced commercially in the United States in 1995 was isolated as a by-product from the manufacture of acrylonitrile by propylene ammoxidation. The amount of acetonitrile produced in an acrylonitrile plant depends on the ammoxidation catalyst that is used, but the ratio of acetonitrile acrylonitrile usually is ca 2—3 100. The acetonitrile is recovered as the water azeotrope, dried, and purified by distillation (28). U.S. capacity (1994) is ca 23,000 t/yr. 

Nitronaphthalene. 1-Nitronaphthalene is manufactured by nitrating naphthalene with nitric and sulfuric acids at ca 40—50°C (37). The product is obtained in very high yield and contains ca 3—10 wt % 2-nitronaphthalene and traces of dinitronaphthalene the product can be purified by distillation or by recrystaUization from alcohol. 1-Nitronaphthalene is important for the manufacture of 1-naphthalenearnine. Photochemical nitration of naphthalene by tetranitromethane in dichioromethane and acetonitrile to give 1-nitronaphthalene has been described (38). 

Economic considerations in the 1990s favor recovering butadiene from by-products in the manufacture of ethylene. Butadiene is a by-product in the C4 streams from the cracking process. Depending on the feedstocks used in the production of ethylene, the yield of butadiene varies. Eor use in polymerization, the butadiene must be purified to 994-%. Cmde butadiene is separated from C and C components by distillation. Separation of butadiene from other C constituents is accomplished by salt complexing/solvent extraction. Among the solvents used commercially are acetonitrile, dimethyl acetamide, dimethylform amide, and /V-methylpyrrolidinone (13). Based on the available cmde C streams, the worldwide forecasted production is as follows 1995, 6,712,000 1996, 6,939,000 1997, 7,166,000 and 1998, 7,483,000 metric tons (14). As of January 1996, the 1995 actual total was 6,637,000 t. 

This type of amination by an oxaziridine is assumed to be the key step of a novel process for hydrazine manufacture, in the course of which butanone in solution with ammonia is reacted with hydrogen peroxide and acetonitrile. The smooth formation of oxaziridines from Schiff bases and hydrogen peroxide-nitrile mixtures is as well known as NH transfer from an oxaziridine like (300), suggesting the intermediacy of (300) as the N—N forming agent (72TL633). 

Oren, Z. et al., Israeli PatentIL 89641, 1995 Chem. Abs., 1996, 124, 260401g It is claimed that a prior method of manufacture from acetonitrile, methanethiol and hydroxylamine hydrochloride gave uncontrolled reaction and explosion. A safer preparation starting from acetaldoxime is claimed. 

Dissolve the isobaric tagging reagents in acetonitrile or ethanol at a concentration of 50 mM (or according to the manufacturer s recommendations). Use a fume hood to handle organic solvents. 

Acetogenins, structural chemistry, 136-8 Acetone, manufacture, 617 Acetonitrile... 

Analysis of aqueous solutions of the polar compounds (DCP, TCP, CA, and DCB) at concentrations of 1-10 ppm was easily accomplished by direct aqueous injection liquid chromatography. The Hamilton PRP-1 reverse-phase column gave a better resolution of these compounds than the conventional reverse-phase columns. Acetonitrile/water mixtures have been found to be as effective as the buffered mobile phases recommended by the manufacturer (28). Analyses of the nonpolar compounds (BHC and DEHP) at concentrations of 25-100 ppb were achieved by XAD resin adsorption-desorption, concentration, and GC techniques. 

Manufacture. Malononitrile can he produced batchwise by elimination ttl waler from cyanoacetamide with phosphorous penlachloride. Most of it is now produced continuously starting from cyanogen chloride and acetonitrile in a high temperature gas phase reaction. 

Most, if not all, of the acetonitrile produced commercially in the United States recently was isolated as a by-product from the manufacture of acrylonitrile by propylene ammoxidation. The acetonitrile is recovered as the water azeotrope, dried, and purified by distillation. 

The advances in column and instrument technology have significantly enhanced HPLC performance in recent years. Results comparing the effects of various column packings on TG separation by RP-HPLC were presented by El-Hamdy and Perkins (87). Six commercially packed columns produced by different manufacturers were used PARTISIL ODS-1 and ODS-2 octadecyl-bonded silica of 10-/rm partical size, ZORBAK-ODS octadecyl-silica of 6-7-/rm diameter (250 X 4.6-mm ID), 5-/rm octyl-bonded spherical silica LC-8, 5-//m methyl-bonded spherical silica LC-1, and a 5-/rm octadecyl-bonded spherical silica LC-18 (150 X 4.6-mm ID). The mobile phase employed consisted of mixtures of methanol/acetone/isopropanol/acetonitrile ranging from l 0 3 4to 1 6 3 4. Triglycerides were solubilized in either THF or acetone at 100 mg/ml for each compound. 

Generally, manufacturers supply aflatoxin as a preweighed dry film in a bottle. This standard can be dissolved in the volume of benzene-acetonitrile required to give a concentration of 8-10 ju,g/ml the actual concentration is measured by UV spectroscopy. At the wavelength of maximum absorption (Amax) the aflatoxin concentration can be calculated using the following formula ... 

A large number of unnatural a-amino acids are commercially available. Many of them are more hydrophobic than natural amino acids. To detect and clearly separate hydrophobic PTH-amino acids using the sequencer, we have extended the elution time from a total of 22 min to 28 min prior to washing the column with 90% solvent B (88% acetonitrile/12% isopropanol, v/v) (Table I). To use the existing software in the protein sequencer to read all 20 PTH-natural amino acids automatically, the first 18 min of the gradient profile is identical to that recommended by the manufacturer. This ensures that the elution profile of natural amino acids remains unchanged. 

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