Nitrile residues

Another aspect is the role of nitrogen in the surface. It was considered that the increase in its concentration after electrolytic oxidation represented exposure of nitrile residues in the core , but recent work by Alexander and Jones demonstrated that the carboxyl groups that form can react with ammonium hydroxide in the aqueous electrolytes to give an amide functionality. 

The increasing vibrational frequency with increasing methacrylonitrile content in the copolymers is consistent with an apparently higher force constant for the CN bond. This can be rationalised in terms of the repulsive forces which exist between the carbon and nitrogen atoms of neighbouring nitrile residues along the polymer chain, and which restrict the vibration of the two atoms in each of the nitrile groups. 

Preparation of benzyl cyanide. Place 100 g. of powdered, technical sodium cyanide (97-98 per cent. NaCN) (CAUTION) and 90 ml. of water in a 1 litre round-bottomed flask provided with a reflux condenser. Warm on a water bath until the sodium cyanide dissolves. Add, by means of a separatory funnel fitted into the top of the condenser with a grooved cork, a solution of 200 g. (181-5 ml.) of benzyl chloride (Section IV.22) in 200 g. of rectified spirit during 30-45 minutes. Heat the mixture in a water bath for 4 hours, cool, and filter off the precipitated sodium chloride with suction wash with a little alcohol. Distil off as much as possible of the alcohol on a water bath (wrap the flask in a cloth) (Fig. II, 13, 3). Cool the residual liquid, filter if necessary, and separate the layer of crude benzyl cyanide. (Sometimes it is advantageous to extract the nitrile with ether or benzene.) Dry over a little anhydrous magnesium sulphate, and distil under diminished pressure from a Claisen flask, preferably with a fractionating side arm (Figs. II, 24, 2-5). Collect the benzyl cyanide at 102-103°/10 mm. The yield is 160 g. 

After cooling to about 40°C (note 2) the viscous brown liquid was poured into a vigorously stirred solution of 50 g of ammonium chloride in 250 ml of 4 N HCl, which was kept at 0-5°C. The flask was also rinsed with this solution. The product was extracted 5-7 times with a 1 1 mixture of diethyl ether and pentane. The combined extracts were washed with saturated NHi Cl solution and subsequently dried over magnesium sulfate. The residue remaining after removal of the solvents in a water-pump vacuum, was carefully distilled through a 30-cm Widmer column. The desired nitrile, b.p. 84°C/15 mmHg, n 1.4487, was obtained in 72% yield. The first fraction (about 5 g) consisted mainly of the 1,3-substitution product n-C,HgC(CsN)=C=CH2. 

Alcohol autoxidation is carried out in the range of 70—160°C and 1000—2000 kPa (10—20 atm). These conditions maintain the product and reactants as Hquids and are near optimum for practical hydrogen peroxide production rates. Several additives including acids, nitriles, stabHizers, and sequestered transition-metal oxides reportedly improve process economics. The product mixture, containing hydrogen peroxide, water, acetone, and residual isopropyl alcohol, is separated in a wiped film evaporator. The organics and water are taken overhead and further refined to recover by-product acetone and the... 

Vmulsifier Type. The manufacturers of NBR use a variety of emulsifiers (most commonly anionic) for the emulsion polymerisation of nitrile mbber. When the latex is coagulated and dried, some of the emulsifier and coagulant remains with the mbber and affects the properties attained with the mbber compound. Water resistance is one property ia particular that is dependent on the type and amount of residual emulsifier. Residual emulsifer also affects the cure properties and mold fouling characteristics of the mbber. 

In 1984 the use of nitrile resins was re-approved by the Food and Drugs Administration with speeifie limits on the level of residual unreacted monomer. 

Ethyl-lsonicotinic Nitrile The 11 grams of the amide just obtained are treated with 15 grams of phosphorus anhydride at 160° to 180°C in a vacuum. 6 grams of a liquid residue are obtained. 

After chilling to -t-12°C, additional methanol (35 ml) and a concentrated aqueous ammoniurt hydroxide solution (1.4M) (100 ml) are added and stirring is continued for 2 hours at a temperature maintained at from -t-5° to -H5°C. The organic layer is separated and solvent is stripped from the aqueous layer at water aspirator pressure at a temperature below 40°C. The residue is extracted several times with chloroform and the chloroform extracts are combined with the separated oil. Chloroform is removed at water aspirator pressure at a temperature below 35°C to leave crude q-amino- -methylmercaptobutyronitrile (methionine nitrile) in 88% yield (68 g) as a clear, somewhat viscous oil. 

The above keto-nitrile (15 grams) was methylated with a solution of diazomethane in ether. (The diazomethane solution was prepared using 20 grams of N-nitrosomethylurea.) The ether and excess diazomethane were evaporated on the steam bath and the oil dissolved in ethanol (50 ml). To this was added a solution of guanidine in ethanol (100 ml) (prepared from 8.1 grams of the hydrochloride). The solution was refluxed for 5 hours, the alcohol removed and the residue treated with 5N sodium hydroxide. The insoluble material was then filtered. After purification by precipitation from dilute acetic acid with sodium hydroxide and by recrystallization from ethanol the product formed clear colorless needles (8.0 grams), MP 218°-220°C as described in U.S. Patent 2,602,794. 

Characterization and understanding of the microstructure become important after hydrogenation and hydroformylation of the nitrile rubber since the amount and distribution of the residual double bonds influence the properties of modified rubber. The conventional analytical tools have been used to characterize the elastomers. Spectroscopy is the most useful technique for determination of the degree of hydrogenation in nitrile rubber. 

A1C1, (0.8 g, 6 mmol) was added to a solution of the chloride 1 (1.6 g, 5.2 mmol) and a nitrile (6 mmol) in 1,2-dichlorobenzene and the mixture was heated at 120-130 C for 20 min. The mixture was cooled, made alkaline with dil aq NaOH and extracted with Et20. The solvents were removed by steam distillation and the residue was chromatographed (silica gel. EtOAc/petroleum ether 1 9) to give the yellow product (deep red if R = Ar). 

Anhyd NH3(g) was bubbled through a stirring mixture of 6,7-di(phenylselanyl)naphthalene-2,3-dicarbo-nitrile (200 mg, 0.43 mmol), NaOMe (0.22 mmol) and 2-methoxyelhanol (5 mL) for 30 min. With continued NH3 introduction, the mixture was heated to 65 "C for 3 h. The solution was evaporated in vacuo. CuCl (21.8 mg, 0.22 mmol) and quinoline (5 mL) were added to the residue and refluxed for 2 h. MeOH was added and the precipitate was filtered, washed with acetone, CH2C12. and toluene yield 105 mg (51 %). 

To a solution of 2.5 g (8.56 mmol) of methyl 4,6-0-(S/5)-benzylidene-2-deoxy-2,2-diniethyl-a-D-3-hexulopy-ranoside, in 100 mL of CH3OH in a stainless steel pressure bottle are added 7 g (130 mmol) of NI14C1 and 8 g (123 mmol) of potassium cyanide. The mixture is cooled to — 78 "C and, under an ammonia gas stream, it is stirred for 30 min. The bottle is then carefully closed and the mixture is stirred for 1 week. The CH3OH is evaporated, and the residue dissolved in CH2C l2, then filtered. Flash chromatography (CII,CI2/hexanc/EiOAc 80 19 1) affords the pure crystalline amino nitrile yield 2 g (73%) mp 152 154°C [a] ,° +1.21 (CHC13). 

Usually. almost the entire crude product distils in this range with practically no fore-run or residue. Occasionally, however, as much as 30 g. of high-boiling residue, chiefly unchanged nitrile, is obtained. When this happens the yield is correspondingly decreased. 

During an attempt at destroying benzyl cyanide residues with sodium hypochlorite, a detonation was caused that was probabiy due to the formation of nitrogen trichloride. However, it might be asked if it was not due to the nitrile group oxidation by the hypochlorite present. 

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