Acidity in glacial acetic acid

Analogous open-chain precursors also lead readily to 1,3-dithiolylium salts. S-a-Oxoalkyl thioesters such as (20) on treatment with perchloric acid in glacial acetic acid and HaS undergo ready cyclization to the 1,3-dithiolylium perchlorate (22) (66AH0.7)39). The oxoalkyl dithioesters (21) are probably intermediates in this cyclization as they themselves undergo cyclization with warm 70% perchloric acid or sulfuric acid (80AHC(27)15l). 

Alkaloids a) 10% chromic acid in glacial acetic acid is applied on top of the sample spot Development is performed after a bnef reaction penod [2]... 

A solution of 3.1 g of (2-benzoyl-4-chlorophenyl-carbamoylmethyl)carbamic acid benzyl ester in 30 cc of 20% hydrobromic acid in glacial acetic acid was stirred for 45 minutes at room temperature. On addition of 175 cc of anhydrous ether, a gummy solid precipitated. After several minutes the ether solution was decanted. The resultant 5-chloro-2-gly-cylaminobenzophenone was not isolated, but about 155 cc of ether was added to the residue and after chilling in an ice bath, 10% sodium hydroxide was added until the mixture was alkaline. The ether layer was then separated, washed twice with water and dried over sodium sulfate. After filtration, the ether solution was concentrated to dryness in vacuo. The residue was crystallized from benzene to yield 7-chloro-5-phenyl-3H-1,4-benzodiazepin-2(1 H)-one. 

The purity of the product can be determined 3 6 by titration in glacial acetic acid, using perchloric acid (in glacial acetic acid) as titrant and methyl violet (0.2 g. of methyl violet in 100 ml. of chlorobenzene) as visual indicator (the first appearance of blue color is taken as the end point). 

As the CH3COOH2+ ion can instantly donate its proton to a base, therefore, a solution of perchloric acid in glacial acetic acid, behaves as a strongly acidic solution. 

The course of a reaction involving At-nitration of an aromatic amine is very dependent on both the substrate and the reaction conditions, i.e. nitrating agent, temperature, work-up etc. The nitration of 3-amino-2,5-dinitrotoluene with mixed acid in glacial acetic acid at 0 °C yields the corresponding diazophenol with no trace of the intermediate nitramine. In contrast, nitration of the same substrate at ambient temperature with mixed acid composed of 90 % nitric acid and 96 % sulfuric acid yields the corresponding nitramine. ... 

Acyloins were converted to mixtures of stereoisomeric vicinal diols by catalytic hydrogenation over copper chromite [972]. More frequently they were reduced to ketones by zinc (yield 77%) [913, 914], by zinc amalgam (yields 50-60%) [975], by tin (yields 86-92%) [173], or by hydriodic acid by refluxing with 47% hydriodic acid in glacial acetic acid (yields 70-90%) [916], or by treatment with red phosphorus and iodine in carbon disulfide at room temperature (yields 80-90%) [917] Procedure 41, p. 215). Since acyloins are readily accessible by reductive condensation of esters (p. 152) the above reductions provide a very good route to ketones and the best route to macro-cyclic ketones [973]. 

In addition to the chemical reactions employed in connection with the degradation reaction, which will be discussed later in detail, it should be mentioned that the nitriles can be transformed into amides (XXV) by treatment with hydrobromic acid in glacial acetic acid, a reaction first applied by ZempMn and Kiss to pentaacetyl-n-glucononitrile (XXIV), and also used by subsequent workers. ... 

Bismuth nitrate reacts with gaUic acid in glacial acetic acid to form bismuth subgaUate, C6H2(OH)3COOBi(OH)2. 

The United States Pharmacopoeia has used a method similar to that of the BP for chlorpromazine, but which uses crystal violet as the indicator [7]. For chlorpromazine hydrochloride, the USP has described its titration with 0.1 M perchloric acid in glacial acetic acid (containing Hg(ll) acetate), and a potentiometric determination of the end point. 

The established procedure for the synthesis of the fused pyrazine ring involves condensation of the oxadiazole diamine with 1,2-dicarbonyl compounds <1978JOC341>. The latter procedure was used by Beebe et al. to make a series of [l,2,5]oxadiazolo[3,4-/ ]pyrazines for evaluation as antibacterial agents <2003BML3133>. An example is shown in Scheme 52, which involved heating the diamine with (3-bromophenyl)oxoacetic acid in glacial acetic acid at 110°C to give the [l,2,5]oxadiazolo[3,4- ]pyrazine. 

Methyl-1,2,4-triazolo[ 1,5-a]pyrimidin-7-on is amphoteric and can be titrated with perchloric acid in glacial acetic acid (61JOC3834). Some derivatives form isolable hydrohalides (75PHA134). Glier et al. (72T5789) formulated a cationic structure at pH 1 from the UV spectrum contrary to that of Hill et al. (61JOC3834). 

Phosphamethin-cyanines, like methin-cyanines, can be protonated by strong acids, forming colorless dications. These can be converted back to the original phosphamethin-cyanines by careful addition of weak bases such as tert.-butanol. This acid-base reaction is least successful in the case of the weakly basic bis-benzthiazole-phosphamethin-cyanine 6. For bis-quinoline-phosphamethin-cyanine 7 b, we obtained vnth perchloric acid in glacial acetic acid the absorption spectrum of the N-ethyl-quinolinium salt. 

Isatin-3-hydrazones (86) react with nitrosylsulfuric acid in glacial acetic acid to give, after dilution with water, the diazonium salt 97 as indicated by the formation of an azo dye with A,A-dimethylaniline.325-... 

Direct nitration of thiophene, using a mild nitrating system at low temperature, gives 2-nitrothiophene in excellent yield. Acetyl nitrate, benzoyl nitrate or copper(I) nitrate in acetic anhydride or acetic acid is commonly used, and only traces of 3-nitrothiophene and 2,5-dinitrothiophene are formed. Slow addition of thiophene dissolved in acetic anhydride to a solution of nitric acid in glacial acetic acid, maintaining the temperature at 10°C, is reported to be the optimum procedure (Section 3.14.2.4.8). 

A complete analogy to the behavior of tneee cyclic compound can be found in the ethylenic series of hydrocarbon. Ethylene and propylene do not react with hydrobroiuic acid in glacial acetic acid,but c °=C . an<1 OhJ- ° C OH do1 thue the introduction of a methyl group ha lncreaaed the reactivity of the uneaturated compound,as it did tne reactivity of cyclopropane. Tne addition of hydrobromic acid givea mainly, the X of tne HX going to the moat... 

Yield.—75% theoretical (10 gms.). Colourless crystals soluble in ether and hot benzene gives a deep red solution in strong sulphuric acid in glacial acetic acid it is colourless, but addition of a drop of concentrated hydrochloric acid gives a deep yellow coloration M.P. 159°. 

Reaction LXX. Oxidation of certain Hydrocarbons. (B., 14, 1944 A. Spl., 1869, 300 E.P., 1948 (1869).)—This reaction is confined in the aliphatic series almost exclusively to the replacement by hydroxyl of the hydrogen attached to tertiary carbon atoms. A powerful oxidising agent, e.g., chromic acid in glacial acetic acid, is necessary. In the aromatic series the reaction is somewhat more easy to accomplish when the sodium salt of anthraquinone-jS-monosulphonic acid, for example, is fused under pressure with caustic soda and a little potassium chlorate, replacement of both a hydrogen atom and the sulphonic acid group by hydroxyl occurs, and alizarin ( /f-dihydroxyanthraquinone) is obtained. 

Benzoyl-1,2-dihydro-1-cyanoisoquinoline was treated with fluoro-boric acid in glacial acetic acid to give the Reissert salt 56 reactions of the latter with EPP, DMAD, and ethyl tetrolate were examined. With EPP, the initial bridged compound 58 was isolated as a moderately stable crystalline compound, and was the first example of an isolated... 

Acidity is a function of both VI the solute and the solvent. HCI is a strong acid in water, a weak acid in glacial acetic acid, and remains undissociated in benzene. Arrhenius theory pertains to aqueous solutions. 

As part of a chemical study of the antibiotic X-537A, 1, the latter was treated with 5 equivalents of concentrated nitric acid in glacial acetic acid. The major product from this reaction was a dinitro derivative of 1 which, on treatment with dilute aqueous sodium hydroxide solution, gave a mixture of products one of which was shown to be 6-hydroxy-2,7-dimethyl-5-nitroquinoline. 

The content of nitrogen bases was determined by anhydrous titration with perchloric acid in glacial acetic acid and expressed as mg. NHs/liter oil (39). 

Lomustine waste can be disposed of by reacting with hydrobromic acid in glacial acetic acid. This method cannot be used for disposing of carmustine, semustine, or PCNU wastes. Accidental overdose of lomustine may be fatal.224... 

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