Hydrochloric acid, hydrolysis by

Schdpf and Thoma found that lupininic acid yielded a methyl ester (b.p. 120-2°/10 mm.) which had [aj — 19-4° to 5-8° in different batches. The f-ester furnished a gummy picrate, [a]J, ° — 41-8°, and on hydrolysis by hydrochloric acid gave a crystalline lupininic acid hydrochloride, m.p. 275°, — 13T°, identical with that described by Willstatter and Fourneau, whilst the d-ester, or ester of f-rotation below — 19-4°, furnished a crystalline picrate, m.p. 185°, [a]j, -f- 61-8°, from which pure d-epi-ester,-b.p. 126°/11 mm., [aJi, 54-8°, was prepared, this in turn yielding amorphous d-lupininie acid hydrochloride. The f-ester is convertible into ... 

For the preparation and estimation of the monoamino acids, hydrolysis by hydrochloric acid is more convenient than that by sulphuric acid. It was formerly carried out in the presence of stannous chloride (Hlasiwetz and Habermann) in order that the solution should remain colourless, instead of becoming dark brown, but this addition is not essential, as was shown by Cohn, and was not used by E. Fischer in his researches. Hydrolysis by hydrochloric acid is carried out by heating the protein with three times its quantity of concentrated hydrochloric acid... 

Schulze, Barbieri and Bosshard next showed that their substance arose during the germination of the seed, and that it was also obtained from vegetable proteins by hydrolysis, by hydrochloric acid and zinc chloride, or by baryta. It was therefore contained in the protein molecule. 

It was also synthesised by E. Fischer in 1901 from 7-phthalimido-propylmalonic ester which he employed in the preparation of ornithine. The bromine derivative of this compound when treated with ammonia gave a complex mixture of products which after hydrolysis by hydrochloric acid at 100° C. gave phthalimide and a-pyrrolidine carboxylic acid —... 

In the early days, greatest interest was focused on the acid-catalyzed hydrolysis (by hydrochloric acid in the presence of 2,4-dinitrophenylhydrazine) of Reissert compounds to aldehydes and the corresponding heterocyclic carboxylic acid derivatives. This reaction is fairly general for compounds of quinoline (178) and isoquinoline (179) (Table 18), but it is not applicable to pyridines as they rarely form Reissert compounds. The 3-hydroxyquino-line Reissert compound does not yield benzaldehyde, probably because acylation of the 3-hydroxy group prevents formation of the required cyclic intermediate (180). Some nitroquinolines and isoquinolines give low yields of benzaldehyde. Rather curiously, disub-stituted quinoline Reissert compounds yield less of the aldehyde than of the corresponding... 

The addition of ammonia to acrylonitrile gives /S-aminopropionitrile and fczs-(/S-cyanoethyl)-amine. The former is hydrolyzed directly to /S-amino-propionic acid (90%) by barium hydroxide, " and the latter may also be converted through the intermediate phthalimide to the same amino acid (6S)%). A variation of this procedure involves condensation of phthalimide and acrylonitrile to /S-phthalimidopropionitrile, Both amino and carboxyl groups are formed during the subsequent hydrolysis by hydrochloric acid. The free /S-alanine (75%) is liberated from the hydrochloride by lithium hydroxide. ... 

Effect of the Aglycoti on Rate of Hydrolysis by Hydrochloric Acid... 

Complete hydrolysis of dicarboxylic esters requires prolonged boiling with alcoholic potassium hydroxide. On alkaline hydrolysis of unsaturated carboxylic esters a double bond may migrate,64 but this does not occur on hydrolysis by hydrochloric acid. 

This reaction was first reported by Hinsberg in 1888. It is the synthesis of N-alkyl-oxindole from IV-alkyl aniline and the glyoxal-bisulfite adduct after hydrolysis by hydrochloric acid. Similarly, the reaction of A -alkyl naphthylamine with glyoxal-bisulfite adduct leads to benzo-oxindole. In contrast, the reaction between primary aryl amines and... 

Innovanamine, 2-methyl-3-0-D-glucopyranosyl-4-pyridone (XII-829) has been isolated from fallen leaves of Evodiopanax innovans and has been prepared from the natural maltol glucoside (XII-828). Hydrolysis by hydrochloric acid in methanol or in the presence of emulsin gives 3-hydroxy-2-methyl-4-pyridone and glucose. ... 

Ravens, D.A.S. The Chemical Reactivity of Poly(ethylene terephthalate) Heterogeneous Hydrolysis by Hydrochloric Acid. Polymer. 1960, 7,375-383. 

Hydrolysis of Benzonitrile. Benzonitrile is moderately readily hydrolysed by 10% aqueous sodium hydroxide, but only slowly by hydrochloric acid (cf. p. 122). Ready hydrolysis is obtained by boiling the nitrile under reflux... 

Hydrolysis of the azlactone leads to the acylaminooinnamic acid the latter may be be reduced catal3rtlcally (Adams PtOj catalyst 40 lb. p.s.i.) and then hydrolysed by hydrochloric acid to the amino acid. Alternatively, the azlactone (say, of a-benzylaminocinnamic acid) may undergo reduction and cleavage with phosphorus, hydriodic acid and acetic anhydride directly to the a-amino acid (d/ p phenylalanine). 

Aiyl benzoates, stable to alkylation conditions using K2C03/Me2S04, are cleaved by more basic hydrolysis (KOH). They are stable to anhydrous hydrogen chloride, but are cleaved by hydrochloric acid ... 

Semicarbazones are prepared in high yields from A " -3-ketones. However, regeneration of the parent dienone is usually difficult and inefficient and very low yields are usually obtained on hydrolysis by nitrous acid, hydrochloric acid or acetic anhydride-pyridine. " In some examples higher yields have been obtained with aqueous acetic acid. ... 

Upon carefully controlled hydrolysis with hydrochloric acid at room temperature, the corresponding serine methyl esters 4 are obtained in reasonable yields. Higher yields of 4 arc obtained by hydrolyzing with dilute trifluoroacetic acid5. In some cases, the diastereomeric ratio of 4 does not exactly correspond to the d.r. of the adduct 3, which is attributed to different kinetics in the hydrolysis of the diastereomers 4. Subsequent treatment of the methyl ester with excess 5 N hydrochloric acid and methyloxirane as an acid scavenger results in the free amino acid 54,7. 

Ethyl o-nitrophenylpyruvate and o-nitrophenylpyruvic acid 14-21 have been prepared by condensation of o-nitrotoluene with diethyl oxalate in the presence of potassium ethoxide,4 14 sodium ethoxide,16-20 or sodium methoxide.21 Sodium ethoxide is less reactive, however, and cannot be substituted successfully for potassium ethoxide in the present procedure, as it gives a very poor yield and poor quality of precipitated sodium salt. With sodium ethoxide the reaction does not appear to go to completion even under the conditions of refluxing ethanol usually employed,16-21 which are considerably more severe than the room temperature conditions employed with potassium ethoxide in the present procedure. o-Nitrophenylpyruvic add has also been prepared by hydrochloric acid hydrolysis of o-nitro-a-acetamino-dnnamic azlactone.4... 

Reactivity Hydrolysis products Hydrochloric acid and chlorovinyl arsenous oxide, a vesicant. The latter is a nonvolatile solid that is not readily washed away by rains. Strong alkalies destroy these blister-forming properties. 

The first constitutional studies were made by Schmiedeberg97 who gave a general idea of the type of structure in chondroitin. Levene considered that the molecule was a tetrasaccharide composed of two glucuronic acid residues conjugated with two units of chondrosamine, esterified with sulfuric acid. On hydrolysis with hydrochloric acid the... 

Relatively pure xylan isolated from the holocellulose of aspen (Populus) wood is said to contain 85% of xylose residues.78 One of the characteristic properties of xylan is its ease of hydrolysis. Because it hydrolyzes much more readily than cellulose, mild acid treatment may be employed to bring about preferential hydrolysis of xylan from plant material. Xylose is ordinarily prepared in the laboratory by direct sulfuric acid hydrolysis of the native xylan in ground corn cobs.74 Hydrolysis in hydrochloric acid proceeds rapidly, but decomposition to furfural also occurs to some extent.76 A commercial method for the production of D-xylose from cottonseed hulls76 and straw77 and from corn cobs17 78 has been described. 

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