Acetone cyanohydrin nitrate nitration with

Caution The nitrating mixture consisting of fuming nitric acid and acetic anhydride is an extremely active one, and combinations of it and organic materials are potentially explosive. The nitration should be carried out behind adequate safety shields. Acetone cyanohydrin nitrate is moderately explosive (Note 6) and all operations with it, but particularly its distillation, should be carried out behind safely shields. 

A. Acetone cyanohydrin nitrate. White fuming nitric acid (106 ml., 158 g., 2.3 moles) (Note 1) is added dropwise to 380 ml. (408 g., 4.00 moles) of acetic anhydride at 3-5° contained in a 2-1. three-necked flask fitted with a stirrer, a thermometer, and a dropping funnel and immersed in an ice bath. After the addition, which requires 45 minutes, the mixture is stirred at 5° for 15 minutes (Note 2). Acetone cyanohydrin (92 ml., 85 g., 1.00 mole) (Note 3) is added dropwise to the mixture at 5-10° over a 45-minute period. After the addition, the ice bath is removed and the mixture is allowed to warm to room temperature and is stirred there for 30 minutes. It is then poured into 600 g. of ice... 

The mixture is extracted with four 100-ml. portions of methylene chloride. The extracts are combined, washed successively with 100 ml. of water and four 100-ml. portions of 5% sodium carbonate solution (Note 4), and dried over anhydrous magnesium sulfate. The methylene chloride is removed by evaporation at 30-40° under the pressure of a water aspirator, and the residue is distilled through a 30-cm. Vigreux column to yield 85-90 g. (65-69%) (Note 5) of acetone cyanohydrin nitrate (Note 6) b.p. 62-65°/10 mm. 1.4170-1.4175 (Note 7). 

B. N-Nitromorpholine. Morpholine (34.8 g., 0.40 mole) and 26 g. (0.20 mole) of acetone cyanohydrin nitrate are mixed in a 50-ml. round-bottomed flask equipped with a thermometer well. A condenser is attached, and the mixture is heated slowly. At about 60° an exotherm ensues that raises the temperature of the mixture to 110°. The mixture is allowed to cool to 80° and maintained there for 1 hour. It is poured into 200 ml. of 10% hydrochloric acid (Caution Do in a hood Note 8) and extracted with three 100-ml. portions of methylene chloride (Note 9). The extracts are combined, washed successively with two 100-ml. portions of water, 100 ml. of 10% hydrochloric acid, and 100 ml. of water, and dried over anhydrous magnesium sulfate. The solvent is removed by evaporation on a water aspirator at room temperature to yield a pale-yellow oil (Note 10). 

Acetone cyanohydrin nitrate, a reagent prepared from the nitration of acetone cyanohydrin with acetic anhydride-nitric acid, has been used for the alkaline nitration of alkyl-substituted malonate esters. In these reactions sodium hydride is used to form the carbanions of the malonate esters, which on reaction with acetone cyanohydrin nitrate form the corresponding nitromalonates. The use of a 100 % excess of sodium hydride in these reactions causes the nitromalonates to decompose by decarboxylation to the corresponding a-nitroesters. Alkyl-substituted acetoacetic acid esters behave in a similar way and have been used to synthesize a-nitroesters. Yields of a-nitroesters from both methods average 50-55 %. 

Acetone cyanohydrin nitrate, a reagent prepared by treating acetone cyanohydrin with nitric acid-acetic anhydride, has been used for the At-nitration of aliphatic and alicyclic secondary... 

Acetone cyanohydrin nitrate will not nitrate amines with branching on the carbon a to the nitrate group. For these substrates the use of ethyl nitrate and lithium bases is favoured. a-Aminonitriles are frequently observed as impurities under the reaction conditions because of the slow decomposition of acetone cyanohydrin nitrate to hydrogen cyanide and acetone. The need for an excess of amine during these reactions is wasteful and only practical if this component is cheap and widely available. Other cyanohydrin nitrates are less efficient N-nitrating agents. ... 

The solid superacidic Nafion-Hhas also been found to catalyze effectively nitration reactions with various reagents.503 The nitrating agents employed were n-butyl nitrate, acetone cyanohydrin nitrate, and fuming nitric acid. In nitric acid nitrations, sulfuric acid can be substituted by Nafion-H and the water formed is azeotropically removed during the reaction (azeotropic nitration).503... 

At present there are four good methods for preparing secondary nitramines. They are the oxidation of nitrosamines by peroxytrifluoro-acetic acid (5), the chloride-ion catalyzed direct nitration of amines (3), the nitrolysis of dialkylamides with nitric acid (16), and the alkaline nitration of amines with acetone cyanohydrin nitrate (6). We have found that treating two equivalents of several secondary aliphatic amines... 

Nitration of chlorobenzene with n-butyl nitrate and a Nafion-H catalyst gave only a 15% yield of the chloronitrobenzenes but with acetone cyanohydrin nitrate a 49% yield was obtained with the para isomer produced with 70% selectivity.65 Using an iron exchanged montmorillonite to promote the nitration of chlorobenzene with nitric acid and acetic anhydride gave a 90% yield of the nitro chlorobenzenes in 15 minutes at 80°C. The para isomer was produced in 92% selectivity (Eqn. 22.28).68... 

Olah [40c] has drawn attention to the fact that the first solid acid catalyst was suggested by Kameo, Nishimura and Manabe (71 ]. They used polystyrene-sulphonic acid with nitric acid, but the system was unstable, as the catalyst was degraded by the strong acid. Olah and associates [72] developed a nitrating agent from n-butyl nitrate and acetone cyanohydrine nitrate by adding a per-... 

Acetone cyanohydrin nitrate, (CH.iladlCN. Mol. wt. 130.11. b.p. 65-66710 mm. Supplier. Aldrich. Preparation by nitration of acetone cyanohydrin with fuming nitric acid and acetic anhydrfde.Tnur/on moderately explosive. 

Alkylation and nitration of malonic esters. Zaugg, using sodium hydride for conversion of n-butylmalonic ester into its sodio derivative, found that the rate of alkylation of this substance with -butyl bromide in dimethylformamide is 1,000 times the rate in benzene. Emmons and Freeman developed a procedure for the nitration of active methylene compounds with acetone cyanohydrin nitrate by conversion to the sodio derivative with sodium hydride. The reaction product (3)... 

Alkylbenzenes are cleanly nitrated in high yields with n-butyl nitrate or acetone cyanohydrin nitrate, catalysed by a perfluorinated resin sulphonic acid (Nafion-H)." The product(s) can be isolated simply by filtration of the catalyst without the need for aqueous basic work-up. 

The product obtained from this distillation usually contains small amounts of acetone cyanohydrin acetate, as evidenced by an ester carbonyl band at 1740 cm.-1 in its infrared spectrum. This material does not interfere with the nitration reactions of the reagent. It may be removed by fractionation through a more efficient column. 

Cyanide and thiocyanate anions in aqueous solution can be determined as cyanogen bromide after reaction with bromine [686]. The thiocyanate anion can be quantitatively determined in the presence of cyanide by adding an excess of formaldehyde solution to the sample, which converts the cyanide ion to the unreactive cyanohydrin. The detection limits for the cyanide and thiocyanate anions were less than 0.01 ppm with an electron-capture detector. Iodine in acid solution reacts with acetone to form monoiodoacetone, which can be detected at high sensitivity with an electron-capture detector [687]. The reaction is specific for iodine, iodide being determined after oxidation with iodate. The nitrate anion can be determined in aqueous solution after conversion to nitrobenzene by reaction with benzene in the presence of sulfuric acid [688,689]. The detection limit for the nitrate anion was less than 0.1 ppm. The nitrite anion can be determined after oxidation to nitrate with potassium permanganate. Nitrite can be determined directly by alkylation with an alkaline solution of pentafluorobenzyl bromide [690]. The yield of derivative was about 80t.with a detection limit of 0.46 ng in 0.1 ml of aqueous sample. Pentafluorobenzyl p-toluenesulfonate has been used to derivatize carboxylate and phenolate anions and to simultaneously derivatize bromide, iodide, cyanide, thiocyanate, nitrite, nitrate and sulfide in a two-phase system using tetrapentylammonium cWoride as a phase transfer catalyst [691]. Detection limits wer Hi the ppm range. 

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