Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Amines anhydrous

Iron(III) chloride forms numerous addition compounds, especially with organic molecules which contain donor atoms, for example ethers, alcohols, aldehydes, ketones and amines. Anhydrous iron(III) chloride is soluble in, for example, ether, and can be extracted into this solvent from water the extraction is more effective in presence of chloride ion. Of other iron(III) halides, iron(III) bromide and iron(III) iodide decompose rather readily into the +2 halide and halogen. [Pg.394]

Aqueous amines anhydrous ammonia aqueous carbonate C02 aqueous hydroxides nitrates... [Pg.432]

DICHLORODIMETHYLSILANE (75-78-5) Forms explosive gas mixture with air (flash point 15°F/—9°C). Contact with water, steam, water vapor, moist air causes decomposition with the formation of hydrogen chloride. Contact with anhydrous ammonia forms a pyrophoric compound. Incompatible with acetone, amines, anhydrous ammonia, alcohols, strong oxidizers, caustics. Flow or agitation of substance may generate electrostatic charges due to low conductivity. Attacks most metals. [Pg.399]

Carbon steels Aqueous amines, anhydrous ammonia, aqueous carbonate, COj, aqueous hydroxides, nitrates... [Pg.9]

They are prepared by the action of HNO2 on aromatic amines. The amine is dissolved in excess of mineral acid and sodium nitrite is added slowly until a slight excess of HNO2 is present. The reaction is usually carried out in ice-cold solution. The solution then contains the diazonium salt of the mineral acid used, anhydrous diazonium salts of unpredictable stability may be precipitated with complex anions like PF , SnCl6 BF4 . [Pg.133]

Although the acetylation of alcohols and amines by acetic anhydride is almost invariably carried out under anhydrous conditions owing to the ready hydrolysis of the anhydride, it has been shown by Chattaway (1931) that phenols, when dissolved in aqueous sodium hydroxide solution and shaken with acetic anhydride, undergo rapid and almost quantitative acetylation if ice is present to keep the temperature low throughout the reaction. The success of this method is due primarily to the acidic nature of the phenols, which enables them to form soluble sodium derivatives, capable of reacting with the acetic... [Pg.109]

A certain amount of hydrolysis of the original acetamide to acid and ammonia always occurs, and the final amine always contains traces of ammonia. This is separated by extracting the mixed anhydrous hydrochlorides with absolute ethanol, which dissolves the amine hydrochloride but not the ammonium chloride filtration of the hot ethanolic extract removes the ammonium chloride, whilst the amine hydrochloride crystallises readily from the filtrate on cooling. [Pg.128]

R NHa + C.HjNCO = RNH CO NHC,Hj Traces of water will contaminate the product with diphenylurea (p. 336) if the solution is boiled hence the need for anhydrous conditions. i-Naphthylisocyanate reacts more slowly with water, and the i-naphthyl-urea derivative can often be obtained using a cold aqueous solution of an aliphatic amine it is particularly necessary in such cases to purify the product by recrystallisation from, or extraction with, boiling petroleum, leaving behind any insoluble di i-naphthylurea. Note that the amine must also be free from alcohols (p. 335) and phenols (p. 337). [Pg.375]

Metallic sodium. This metal is employed for the drying of ethers and of saturated and aromatic hydrocarbons. The bulk of the water should first be removed from the liquid or solution by a preliminary drying with anhydrous calcium chloride or magnesium sulphate. Sodium is most effective in the form of fine wire, which is forced directly into the liquid by means of a sodium press (see under Ether, Section II,47,i) a large surface is thus presented to the liquid. It cannot be used for any compound with which it reacts or which is affected by alkalis or is easily subject to reduction (due to the hydrogen evolved during the dehydration), viz., alcohols, acids, esters, organic halides, ketones, aldehydes, and some amines. [Pg.143]

When ammonium chloride is heated to a higher temperature (160°) with a large excess of anhydrous formaldehyde (as paraformaldehyde), trimethyl-amine hydrochloride (trimethylammonium chloride) may be obtained ... [Pg.414]

The independent preparation of potassium phthabmide (from a solution of phthalimide in absolute ethanol and potassium hydroxide in 75 per cent, ethanol) may be avoided in many cases by boiling phthalimide with the halide in the presence of anhydrous potassium carbonate. The N-substituted phthalimide (I) is frequently cleav with difficulty this is often facilitated by reaction with hydrazine hydrate to give an intermediate product, which is easily decomposed by hydrochloric acid to 3deld the insoluble hydrazide of phthaUc acid (II) and the primary amine (III) ... [Pg.560]

P-Phenylethylamine is conveniently prepared by the hydrogenation under pressure of benzyl cyanide with Raney nickel catalyst (see Section VI,5) in the presence of either a saturated solution of dry ammonia in anhydrous methyl alcohol or of liquid ammonia the latter are added to suppress the formation of the secondary amine, di- P phenylethylamine ... [Pg.560]

Dissolve 1 0 g. (or 10 ml.) of the amine and 1 0 g. of 2 4-dinitrochloro-benzene in 5-10 ml. of ethanol, add a slight excess of anhydrous potassium carbonate or of powdered fused sodium acetate, reflux the mixture on a water bath for 20-30 minutes, and then pour into water. Wash the precipitated solid with dilute sodium carbonate solution, followed by dilute hydrochloric acid. Recrystallise from ethanol, dilute alcohol or glacial acetic acid. [Pg.654]

In a 500 ml. flask, fitted with a reflux condenser, place 53 g. of 1-chloro-methylnaphthalene (Section IV.23), 84 g, of hexamethylenetetramine and 250 ml. of 1 1 acetic acid [CAUTION 1-Chloromethylnaphtha-lene and, to a lesser degree, a-naphthaldehyde have lachrymatory and vesicant properties adequate precautions should therefore be taken to avoid contact with these substances.] Heat the mixture under reflux for 2 hours it becomes homogeneous after about 15 minutes and then an oil commences to separate. Add 100 ml. of concentrated hydrochloric acid and reflux for a further 15 minutes this will hydrolyse any SchifiF s bases which may be formed from amine and aldehyde present and will also convert any amines into the ether-insoluble hydrochlorides. Cool, and extract the mixture with 150 ml. of ether. Wash the ether layer with three 50 ml. portions of water, then cautiously with 50 ml. of 10 per cent, sodium carbonate solution, followed by 50 ml. of water. Dry the ethereal solution with anhydrous magnesium sulphate, remove the ether by distillation on a steam bath, and distil the residue under reduced pressure. Collect the a-naphthaldehyde at 160-162718 mm. the yield is 38 g. [Pg.700]

Hydrolysis of a sulphonamide. Mix 2 g. of the sulphonamide with 3-5 ml. of 80 per cent, sulphuric acid in a test-tube and place a thermometer in the mixture. Heat the test-tube, with frequent stirring by means of the thermometer, at 155-165° until the solid passes into solution (2-5 minutes). Allow the acid solution to cool and pour it into 25-30 ml. of water. Render the resulting solution alkaline with 20 per cent, sodium hydroxide solution in order to liberate the free amine. Two methods may be used for isolating the base. If the amine is volatile in steam, distil the alkaline solution and collect about 20 ml. of distillate extract the amine with ether, dry the ethereal solution with anhydrous potassium carbonate and distil off the solvent. If the amine is not appreciably steam-volatile, extract it from the alkaline solution with ether. The sulphonic acid (as sodium salt) in the residual solution may be identified as detailed under 13. [Pg.1077]

A suspension of sodium amide in 500 ml of anhydrous liquid artmonia was prepared from 18 g of sodium (see Chapter II, Exp. 11). To the suspension was added in 10 min with swirling a mixture of 0.30 mol of 1-chloro-l-ethynylcyclohexane (see VIII-2, Exp. 27) and 50 ml of diethyl ether. The reaction was very vigorous and a thick suspension was formed. The greater part of the ammonia was evaporated by placing the flask in a water bath at 50°C. After addition of 500 ml of ice-water the product was extracted three times with diethyl ether. The ethereal extracts were dried over anhydrous KjCOj and subsequently concentrated in a water-pum vacuum. Distillation of the residue afforded the amine, b.p. 54°C/15 mmHg, n 1.4345, in 87% yield. [Pg.230]

In production, anhydrous formaldehyde is continuously fed to a reactor containing well-agitated inert solvent, especially a hydrocarbon, in which monomer is sparingly soluble. Initiator, especially amine, and chain-transfer agent are also fed to the reactor (5,16,17). The reaction is quite exothermic and polymerisation temperature is maintained below 75°C (typically near 40°C) by evaporation of the solvent. Polymer is not soluble in the solvent and precipitates early in the reaction. [Pg.58]

Ammonium fluorosulfate is produced from ammonium fluoride by reaction with sulfur trioxide, oleum, or potassium pyrosulfate, 1 2820 (48). Solutions of ammonium fluorosulfate show Htfle evidence of hydrolysis and the salt may be recrystallized from hot water. Ammonium fluorosulfate absorbs anhydrous ammonia to form a series of Hquid amines that contain 2.5—6 moles of ammonia per mole of salt (77). [Pg.250]

Fluorocarbons are made commercially also by the electrolysis of hydrocarbons in anhydrous hydrogen fluoride (Simons process) (14). Nickel anodes and nickel or steel cathodes are used. Special porous anodes improve the yields. This method is limited to starting materials that are appreciably soluble in hydrogen fluoride, and is most useflil for manufacturing perfluoroalkyl carboxyflc and sulfonic acids, and tertiary amines. For volatile materials with tittle solubility in hydrofluoric acid, a complementary method that uses porous carbon anodes and HF 2KF electrolyte (Phillips process) is useflil (14). [Pg.283]

Fluoroaromatics are produced on an industrial scale by diazotization of substituted anilines with sodium nitrite or other nitrosating agents in anhydrous hydrogen fluoride, followed by in situ decomposition (fluorodediazoniation) of the aryldiazonium fluoride (21). The decomposition temperature depends on the stabiHty of the diazonium fluoride (22,23). A significant development was the addition of pyridine (24), tertiary amines (25), and ammonium fluoride (or bifluoride) (26,27) to permit higher decomposition temperatures (>50° C) under atmospheric pressure with minimum hydrogen fluoride loss. [Pg.318]

The single-step -duoroaruline [31-40-4] process based on duorodeoxygenation of nitrobenzene (via in situ generation of /V-phenylhydroxyl amine) in anhydrous hydrogen duoride (94—96) has not been commercialized primarily due to concurrent formation of aniline, as well as limited catalyst life. The potential attractiveness of this approach is evidenced by numerous patents (97—101). Concurrent interest has been shown in the two-step process based on /V-phenylhydroxylamine (HF-Bamberger reaction) (102—104). [Pg.319]

Chloro-2,4,6-trifluoropyrimidine [697-83-6] has gained commercial importance for the production of fiber-reactive dyes (465,466). It can be manufactured by partial fluoriaation of 2,3,5,6-tetrachloropyrimidine [1780-40-1] with anhydrous hydrogen fluoride (autoclave or vapor phase) (467) or sodium fluoride (autoclave, 300°C) (468). 5-Chloro-2,4,6-trifluoropyrimidine is condensed with amine chromophores to provide the... [Pg.340]

The salt is extremely hydroscopic and is used in dehumidification appHcations. It is very soluble in water (Table 4). The hydrates LiCl 2H20 [16712-19-9] and LiCl H2O [16712-20-2] precipitate at temperatures below 100°C. The anhydrous salt precipitates at 100°C. The salt has appreciable solubiHty in alcohols and amines. [Pg.225]

The free maleic acid content in maleic anhydride is determined by direct potentiometric titration (166). The procedure involves the use of a tertiary amine, A/-ethylpipetidine [766-09-6J, as a titrant. A tertiary amine is chosen as a titrant since it is nonreactive with anhydrides (166,167). The titration is conducted in an anhydrous solvent system. Only one of the carboxyhc acid groups is titrated by this procedure. The second hydrogen s dissociation constant is too weak to titrate (166). This test method is not only used to determine the latent acid content in refined maleic acid, but also as a measure of the sample exposure to moisture during shipping. [Pg.459]

Oxalyl Chloride. This diacid chloride [79-37-8], ClCOCOCl, mol wt 126.9, is produced by the reaction of anhydrous oxaUc acid and phosphoms pentachloride. The compound vigorously reacts with water, alcohols, and amines, and is employed for the synthesis of agrochemicals, pharmaceuticals, and fine chemicals. [Pg.463]

Commercially, pure ozonides generally are not isolated or handled because of the explosive nature of lower molecular weight species. Ozonides can be hydrolyzed or reduced (eg, by Zn/CH COOH) to aldehydes and/or ketones. Hydrolysis of the cycHc bisperoxide (8) gives similar products. Catalytic (Pt/excess H2) or hydride (eg, LiAlH reduction of (7) provides alcohols. Oxidation (O2, H2O2, peracids) leads to ketones and/or carboxyUc acids. Ozonides also can be catalyticaHy converted to amines by NH and H2. Reaction with an alcohol and anhydrous HCl gives carboxyUc esters. [Pg.494]

Lactams can also be polymerized under anhydrous conditions by a cationic mechanism initiated by strong protic acids, their salts, and Lewis acids, as weU as amines and ammonia (51—53). The complete reaction mechanism is complex and this approach has not as yet been used successfully in a commercial process. [Pg.224]


See other pages where Amines anhydrous is mentioned: [Pg.307]    [Pg.328]    [Pg.385]    [Pg.27]    [Pg.113]    [Pg.264]    [Pg.265]    [Pg.475]    [Pg.690]    [Pg.691]    [Pg.345]    [Pg.307]    [Pg.328]    [Pg.385]    [Pg.27]    [Pg.113]    [Pg.264]    [Pg.265]    [Pg.475]    [Pg.690]    [Pg.691]    [Pg.345]    [Pg.142]    [Pg.419]    [Pg.573]    [Pg.66]    [Pg.107]    [Pg.134]    [Pg.128]    [Pg.269]    [Pg.273]    [Pg.454]   
See also in sourсe #XX -- [ Pg.755 ]




SEARCH



© 2024 chempedia.info