Nitrosyl chloride process

The U.S. domestic commercial potassium nitrate of the 1990s contains 13.9% N, 44.1% I+O, 0—1.8% Cl, 0.1% acid insoluble, and 0.08% moisture. The material is manufactured by Vicksburg Chemical Co. using a process developed by Southwest Potash Division of AMAX Corp. This process uses highly concentrated nitric acid to catalyze the oxidation of by-product nitrosyl chloride and hydrogen chloride to the mote valuable chlorine (68). The much simplified overall reaction is... 

Limonene (+15) is an important raw material for producing (-)-carvone [6485-40-1]. The process uses nitrosyl chloride and proceeds via nitrosochloride and oxime (78,79). The (-)-carvone (40) is found as the main component of spearmint oil and the (+)-carvone produced from (—)-limonene has the characteristic odor of diU. 

Toray. The photonitrosation of cyclohexane or PNC process results in the direct conversion of cyclohexane to cyclohexanone oxime hydrochloride by reaction with nitrosyl chloride in the presence of uv light (15) (see Photochemical technology). Beckmann rearrangement of the cyclohexanone oxime hydrochloride in oleum results in the evolution of HCl, which is recycled to form NOCl by reaction with nitrosylsulfuric acid. The latter is produced by conventional absorption of NO from ammonia oxidation in oleum. Neutralization of the rearrangement mass with ammonia yields 1.7 kg ammonium sulfate per kilogram of caprolactam. Purification is by vacuum distillation. The novel chemistry is as follows ... 

Of the other routes the photonitrosation process involving nitrosyl chloride is in use in Japan. This avoids, at the expense of complicated purification processes, the high yields of ammonium sulphate unavoidably produced in the route involving the Beckmann rearrangement. 

The combined liquors, which comprise an aqueous hydrochloric acid solution of 3-amino-methyl-pyridine hydrochloride, are then heated to a temperature of 60° to 65°C, and ethyl nitrite gas is passed into the heated solution. The ethyl nitrite is generated by placing 20 liters of 90% ethyl alcohol in a suitable vessel, diluting with 200 liters of water, and, while stirring, adding to the dilute alcohol 18.3 kg of nitrosyl chloride at the rate of 2.25 kg per hour. (The process using methyl nitrite is carried out by substituting a stoichiometrically equivalent quantity of methyl alcohol for the ethyl alcohol.)... 

Future developments are expected not only to yield a greater understanding of the mechanisms of many photochemical reactions, but also to provide a means for the adaptation of these reactions to large-scale industrial syntheses. A glimpse of the latter is seen in the production of e-caprolactam (Nylon 6 monomer) by the Toyo Rayon Company using the photonitrosation of cyclohexane. In this process nitrosyl chloride is cleaved by light and the following sequence of reactions takes place ... 

Kel-Chlor [Kellogg Chlorine] A non-catalytic version of the Deacon process for making chlorine by oxidizing hydrochloric acid, in which nitrosyl sulfuric acid and nitrosyl chloride are intermediates and concentrated sulfuric acid is used as a dehydrating agent ... 

PNC [Photonitrosation of cyclohexane] A photochemical process for making caprolactam (a precursor for nylon) from cyclohexane, nitrosyl chloride, and hydrogen chloride. The first photochemical product is cyclohexanone oxime ... 

Salt An obsolete, two-stage process for obtaining chlorine and sodium nitrate from sodium chloride by the intermediary of nitrosyl chloride. In the first stage, the sodium chloride was reacted with nitric acid, producing nitrosyl chloride and chlorine ... 

Potassium nitrate may be produced by several methods. It is made commercially by reacting potassium chloride with nitric acid at high temperature. Nitrosyl chloride, a product obtained in the reaction, is converted into chlorine in this manufacturing process. Also, nitric acid is partly recycled in the process. The reactions are (Dancy, W.B. 1981. Potassium Compounds. In Kirk-Othmer Encyclopedia of Chemical Technology, 3 i ed. Pp. 939-42. New York Whey Interscience) ... 

The main renewable resource for L-carvone is spearmint oil (Mentha spicata), which contains up to 75% of this flavour chemical. There also exists a synthetic process for the manufacturing of L-carvone, which is based on (-t)-limonene, which is available as a by-product of the citrus juice industry as a major component of orange peel oil (Scheme 13.4). The synthesis was developed in the nineteenth century and starts with the reaction of (-t)-limonene and nitrosyl chloride, which ensures the asymmetry of the ring. Treatment with base of the nitrosyl chloride adduct results in elimination of hydrogen chloride and rearrangement of the nitrosyl function to an oxime. Acid treatment of the oxime finally results in l-carvone. 

Aziridines can undergo loss of a nitrogen atom in a number of ways and this process is frequently stereospecific in terms of the alkene formed. For example, the reaction of aziridines, e.g. (268), with nitrosating agents such as nitrosyl chloride or methyl nitrite results in the formation of alkenes wit.h greater than 99% stereoselective deamination (64JOC1316). Such transformations proceed via N- nitrosoaziridine intermediates which are isolable at temperatures below -20 °C, but which decompose to the observed products at higher temperatures. 

Somewhat analogous to the Reed process is a recent development in which an olefin is reacted with nitrosyl chloride to form a nitrosyl halide, which in turn is converted to a mixture of complex sulfonates by reaction with sodium sulfite (4). These materials are reported to be excellent metal cleaning detergents. 

It Appears that dinitrogen tetroxide functions as rutrosyl nitrate, in analogy with nitrosyl chloride, forming an oxonium-typo intermediate (Eq. 042). Attack by nitrate ion upon the latter gives rise to the observed product, which in turn reacts further by the same process. 

The extent to which the rate coefficients in Tables 3 and 4 approach that expected for a diffusion-controlled process is illustrated in Fig. 1. For the less reactive amines, nitrosyl chloride reacts significantly faster than nitrosyl... 

Other processes for making chlorine include sodium manufacture, caustic potash manufacture, hydrogen chloride decomposition, the nitro-syl chloride (NOC1) process, and a process where salt is treated with nitric acid to form sodium nitrate and chlorine with nitrosyl chloride (containing 4 to 10% nitrogen tetroxide) as a by-product. The nitrosyl chloride vapor is placed in contact with oxygen to produce nitrogen tetroxide and chlorine ... 

The catalytic oxidation of cyclohexane is performed in the liquid phase with air as reactant and in the presence of a catalyst. The resulting product is a mixture of alcohol and ketone (Table 1, entry 12) [19]. To limit formation of side-products (adipic, glutaric, and succinic acids) conversion is limited to 10-12 %. In a process developed by To ray a gas mixture containing HC1 and nitrosyl chloride is reacted with cyclohexane, with initiation by light, forming the oxime directly (Table 1, entry 12). The corrosiveness of the nitrosyl chloride causes massive problems, however [20]. The nitration of alkanes (Table 1, entry 13) became important in a liquid-phase reaction producing nitrocyclohexane which was further catalytically hydrated forming the oxime. 

Acyl and perfluoroalkyl diazomethanes react with nitrogen oxides, and a-diazosulfones with nitrosyl chloride or dinitrogen trioxide, to give furoxans. The process is believed to involve nitrosation, followed by loss of nitrogen to form the nitrile oxide which subsequently dimerizes. Nitrosation of dimethylphenacylsulfonium bromide with nitric acid/sodium nitrite gives dibenzoylfuroxan. 

This equation is somewhat simplified in fact there are more products formed during the process. Nitrosyl chloride, NOC1, is one of the products which can easily be identified. The oxidative action of chlorine is based on the process described in the previous section. The dissolution of gold can be expressed with the equation ... 

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