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Starch reaction with amines

Cationic Starches. The two general categories of commercial cationic starches are tertiary and quaternary aminoalkyl ethers. Tertiary aminoalkyl ethers are prepared by treating an alkaline starch dispersion with a tertiary amine containing a P-halogenated alkyl, 3-chloto-2-hydtoxyptopyl radical, or a 2,3-epoxypropyl group. Under these reaction conditions, starch ethers are formed that contain tertiary amine free bases. Treatment with acid easily produces the cationic form. Amines used in this reaction include 2-dimethylaminoethyl chloride, 2-diethylaminoethyl chloride, and A/-(2,3-epoxypropyl) diethylamine. Commercial preparation of low DS derivatives employ reaction times of 6—12 h at 40—45°C for complete reaction. The final product is filtered, washed, and dried. [Pg.345]

In the context of synthesis and exchange reactions of biodegradable drug-binding matrices, starch trisuccinic acid was loaded via imidazolides with amines such as n-butylamine, morpholine, 4-aminobenzoic acid, or 3,4-dihydroxyphenylalanine to prepare the respective amides in high yields [160] an example is presented below. [Pg.127]

This method was reported before as a convenient way to couple drugs to dextran and starch (7). For the attachment of alcohols this method is obviously only practical when using the tri-ester derivatives in order to avoid intra- or inter-molecular reactions during the subsequent coupling procedures. However also with amine type drugs similar competitive side reaction may occur as will be illustrated. [Pg.190]

Although consumption of the hydroperoxide is normally complete, the absence of this peroxide in the reaction mixture should be established by testing with moist starch-iodide paper or by iodometric titration.2 The amine oxide content may be determined by titration with standard aqueous hydrochloric acid after any amine present has been consumed by reaction with methyl iodide for 1 hour at room temperature.3 From this volumetric analysis the submitters determined the yield of amine oxide to be 86%. The checkers found that the reaction could be followed by measuring the n.m.r. spectra in -butyl alcohol solution where the n.m.r. N-methyl signals of the amine (at S 2.03) and the amine oxide (at S 2.98) are readily observed. [Pg.57]

The bulk material may ignite or explode in storage. Traces of water may initiate the reaction. A rapid exothermic decomposition above 175°C releases oxygen and chlorine. Moderately explosive in its solid form when heated. Explosive reaction with acetic acid + potassium cyanide, amines, ammonium chloride, carbon or charcoal + heat, carbon tetrachloride + heat, N,N-dichloromethyl-amine + heat, ethanol, methanol, iron oxide, rust, 1-propanethiol, isobutanethiol, turpentine. Potentially explosive reaction with sodium hydrogen sulfate + starch + sodium carbonate. Reaction with acetylene or nitrogenous bases forms explosive products. [Pg.763]

Various aminoalkyl and alkylaminoalkyl halides react with starch in alkaline media and are readily available by the reaction of epichlorohydrin with primary, secondary, and tertiary amines and even aqueous ammonia. Prior to the reaction with starch, the quaternary ammonium compounds were either decomposed to free amines, or they reacted as amminium compounds to give cationic aminium starches. Cationic starches were produced by the reaction of starch with arylalky-laminoalkyl epoxides. In the presence of formaldehyde, inorganic ammonium salts provided the source of amino groups.1316... [Pg.272]

Starch dialdehyde condenses readily with amino amides2624 and diamines,2625 and forms oximes with hydroxylamine.2626 The reaction of starch dialdehyde with isoniazid, 4 -formacelanilide thiosemicarbazone, 4 - amin o b e n z a I de h y de thiosemicarbazone or thiosemicarbazone, produced the corresponding condensation products.613-615 617 2627-2629 Hydrazones were readily formed when hydrazine and its derivatives were blended with starch dialdehyde and acidified with acetic acid2543,2630 or simply on heating the reaction mixture.2631 Condensation of starch... [Pg.285]

Some of the innumerable reagents used in TEC are based on reactions with more or less well-established mechanism. Eor example, sodium iodobismuthate (Dragendorff reagent) is widely used among others for alkaloids and quaternary ammonium compounds, 4-dimethylaminobenzaldehyde for primary amines and amino acids, 2,4-dinitrophenylhydrazine for aldehydes and ketones, ninhydrin for amino acids and some antibiotics, fluorescamine for primary and secondary amines, phosphomolybdic acid for lipids, various steroids, and other compounds, chlorine vapor followed by Kl/starch for amines and amides. More complex is the mechanism of the reactions with some other reagents, containing high concentrations of sulfuric acid, vanillin/sulfuric acid, phosphoric acid, aluminum chloride, antimony(III)... [Pg.843]

Nitrous add reacts rapidly but not instantaneously with amines. Consequently, in testing for completion of the reaction (presence of mreacted nitrous acid), the starch-iodide test for free nitrous add should not be applied until 5 minutes after the addition of a portion of the sodium nitrite solution. [Pg.68]

The experimental conditions necessary for the preparation of a solution of a diazonium salt, diazotisation of a primary amine, are as follows. The amine is dissolved in a suitable volume of water containing 2 5-3 equivalents of hydrochloric acid (or of sulphuric acid) by the application of heat if necessary, and the solution is cooled in ice when the amine hydrochloride (or sulphate) usually crystallises. The temperature is maintained at 0-5°, an aqueous solution of sodium nitrite is added portion-wise until, after allowing 3-4 minutes for reaction, the solution gives an immediate positive test for excess of nitrous acid with an external indicator—moist potassium iodide - starch paper f ... [Pg.590]

Many of these reactions are reversible, and for the stronger nucleophiles they usually proceed the fastest. Typical examples are the addition of ammonia, amines, phosphines, and bisulfite. Alkaline conditions permit the addition of mercaptans, sulfides, ketones, nitroalkanes, and alcohols to acrylamide. Good examples of alcohol reactions are those involving polymeric alcohols such as poly(vinyl alcohol), cellulose, and starch. The alkaline conditions employed with these reactions result in partial hydrolysis of the amide, yielding mixed carbamojdethyl and carboxyethyl products. [Pg.133]

In the context of the stability of the nitrosoamine intermediate in the diazotization of heteroaromatic amines relative to that in the case of aromatic amines, the reversibility of diazotization has to be considered. To the best of our knowledge the reverse reaction of a diazotization of an aromatic amine has never been observed in acidic solutions. This fact is the basis of the well-known method for the quantitative analysis of aromatic amines by titration with a calibrated solution of sodium nitrite (see Sec. 3.3). With heteroaromatic amines, however, it has been reported several times that, when using amine and sodium nitrite in the stoichiometric ratio 1 1, after completion of the reaction nitrous acid can still be detected with Kl-starch paper,... [Pg.62]

Note This reagent sequence is a modiflcation of the reagent chlorine — potassium iodide — starch . Mobile phases containing ammonia must be removed completely before treatment with the reagent sequence, since otherwise the background will be colored too. Some secondary amines (e.g. diphenylamine) and some amides (e.g. 2,4-dinitrobenzamide) and methionine sulfoxide do not give reactions even in quantities of up to 1 to 2 (ig. [Pg.45]

This procedure may be used for the preparation of a variety of a-amino ketones as is indicated in Table I, which summarizes most of the submitters experience with this reaction. Principal deviations from the procedure wifi be in the time required for a negative starch-iodide test and the nature and amount of extraction and recrystallization solvent. It is strongly recommended that any one using the reaction for the first time carry out the preparation on a-phenylethylamine before attempting to use it on other more valuable amines. [Pg.45]

To 450 cc. of concentrated hydrochloric acid (sp. gr. 1.19) and 500 cc. of water in a 4-I. (i-gal.) earthenware crock equipped with an efficient stirrer is added 143 g. (1 mole) of /3-naphthyla-mine. The suspension of the amine hydrochloride is cooled by the addition of 500 g. of cracked ice. When the temperature reaches 5° solid sodium nitrite (about 69 g.) is added until starch-iodide paper shows an excess. During the diazotization about 600 g. of cracked ice is introduced at such a rate as to keep the temperature at 50. The cold solution of the diazonium salt is filtered to remove a small amount of precipitate and returned to the crock. A solution of 271 g. (1 mole) of mercuric chloride in 300 cc. of concentrated hydrochloric acid is mixed with 300 g. of ice and added slowly to the rapidly stirred solution. A heavy yellow solid separates. Stirring is continued for one-half hour to secure complete reaction. The yellow addition compound of /3-naphthalene diazonium chloride and mercuric chloride is collected on a 20-cm. Buchner funnel, sucked as dry as possible, and then washed with two 400-cc. portions of water and two 150-cc. portions of acetone (Note 1). The... [Pg.54]


See other pages where Starch reaction with amines is mentioned: [Pg.665]    [Pg.648]    [Pg.648]    [Pg.648]    [Pg.663]    [Pg.1430]    [Pg.446]    [Pg.104]    [Pg.648]    [Pg.104]    [Pg.216]    [Pg.232]    [Pg.275]    [Pg.278]    [Pg.291]    [Pg.648]    [Pg.731]    [Pg.160]    [Pg.579]    [Pg.40]    [Pg.82]    [Pg.450]    [Pg.61]    [Pg.57]    [Pg.184]    [Pg.186]    [Pg.242]    [Pg.223]    [Pg.630]   
See also in sourсe #XX -- [ Pg.701 ]




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Reaction with amines

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