STUDIES ON LIGNIN AND RELATED COMPOUNDS: XX. METHANOL LIGNIN AND ITS RELATION TO THE SO-CALLED "PRIMARY LIGNIN" OF FRIEDRICH AND DIWALD

1936 ◽  
Vol 14b (1) ◽  
pp. 12-19
Author(s):  
E. G. King ◽  
Harold Hibbert
Keyword(s):  
Structural Change ◽  
Hydrochloric Acid ◽  
Sodium Bicarbonate ◽  
Prolonged Treatment ◽  
Carboxyl Groups ◽  
Preliminary Treatment ◽  
Wood Meal ◽  
Spruce Wood ◽  
And Behavior ◽  
Related Compounds

Pretreatment of spruce wood meal with cold 5% sodium hydroxide decreases the amount of lignin extractable with methanol and anhydrous hydrogen chloride (Hibbert-Brauns method). Such a prior treatment of the wood meal, either in an atmosphere of nitrogen or of air, apparently causes no structural change in the lignin as judged by the methoxyl content. The method of Friedrich and Diwald, which involves a preliminary treatment with 17% hydrochloric acid followed by addition of a hot alcohol, represents a much more drastic process than the Hibbert-Brauns method, as is indicated by the darker color, lower methoxyl content and behavior towards 8–10% alkali of the isolated lignin.Methanol lignin isolated front a resin-free spruce wood meal, previously subjected to treatment with 5% cold alkali in the presence or absence of air, shows no loss of methoxyl groups on treatment with 8–10% alkali; the same is true of the "primary lignin" prepared by the method of Friedrich and Diwald; in both cases the lignin is insoluble in sodium bicarbonate. These facts show that neither methanol lignin nor "native lignin" contains ester methoxyl groups, as assumed by Friedrich and Diwald. Prolonged treatment of methanol lignin with alkali in the presence of air, especially at higher temperatures, apparenthy brings about certain changes in its structure, including possibly the formation of carboxyl groups. The claim of Friedrich and Diwald that their product represents an "unchanged native lignin" is not in accordance with the facts, and their assumption of the presence of carboxyl groups in native lignin is incorrect.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: XII. METHANOL LIGNIN

1935 ◽  
Vol 13b (1) ◽  
pp. 28-34 ◽  
Author(s):  
Fritz Brauns ◽  
Harold Hibbert
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Methyl Alcohol ◽  
Empirical Formula ◽  
Dimethyl Sulphate ◽  
Compound A ◽  
Wood Meal ◽  
Building Unit ◽  
Spruce Wood ◽  
Related Compounds

Methanol lignin was prepared by extracting spruce wood meal with absolute methyl alcohol, using hydrochloric acid as catalyst. In five small, bomb-tube experiments, methanol lignin preparations having the same methoxyl content (about 21.6%) were obtained, the product in each case being apparently homogeneous. The methanol lignin was acetylated, partially methylated by treatment with diazomethane, and fully methylated with dimethyl sulphate and sodium hydroxide. From the elementary analyses and the ratio of methoxyl in the original methanol lignin to that in the diazomethane-methylated compound a formula for the smallest building unit of the methanol lignin and for the native lignin can be derived. The latter is represented by the empirical formula C47H52O16, or, expanded, C42H32O6(OCH3)5(OH)5.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: II GLYCOL-LIGNIN AND GLYCOL-ETHER-LIGNIN

1930 ◽  
Vol 2 (6) ◽  
pp. 364-375 ◽  
Author(s):  
Harold Hibbert ◽  
Léo Marion
Keyword(s):  
Ethylene Glycol ◽  
Monomethyl Ether ◽  
Glycol Ether ◽  
Free Alcohol ◽  
Wood Meal ◽  
Spruce Wood ◽  
Related Compounds

The extraction of spruce wood meal with ethylene glycol in the presence of 0.05% HCl leads to the isolation of a lignin derivative to which the name glycol-lignin is given. If the monomethyl ether of glycol be substituted for the free alcohol, a glycol-ether-lignin is obtained which has a much higher methoxyl content than glycol-lignin. The product of extraction is therefore a compound of lignin and the solvent. A comparison of the methoxyl content of the derivatives obtained from the two lignins by methylation and hydrolysis supports this conclusion. On oxidation, glycol-lignin gives rise to a product which forms a p-bromphenylhydrazone, identical with that obtained from the product of the oxidation of ethylene glycol under the same conditions. On hydrolysis with acids glycol-lignin yields, besides 0.7% formaldehyde, a substance which reduces Fehling's solution.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: III. GLYCEROL-CHLOROHYDRIN-LIGNIN

1930 ◽  
Vol 3 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Harold Hibbert ◽  
John Bernard Phillips
Keyword(s):  
Previous Evidence ◽  
Wood Meal ◽  
Spruce Wood ◽  
Extraction Agent ◽  
Related Compounds

Glycerol α-monochlorohydrin has been found to be an effective extraction agent for the removal of lignin from spruce wood meal. Previous evidence for the view that a compound is formed between the lignin and the extraction medium is supported by the results of methoxyl and halogen analysis, and those of hydrolysis.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: I. A NEW METHOD FOR THE ISOLATION OF SPRUCE WOOD LIGNIN

1930 ◽  
Vol 2 (6) ◽  
pp. 357-363 ◽  
Author(s):  
Harold Hibbert ◽  
H. J. Rowley
Keyword(s):  
Hydrochloric Acid ◽  
Ethylene Glycol ◽  
Ethyl Ether ◽  
Cold Water ◽  
New Method ◽  
Large Excess ◽  
Spruce Wood ◽  
Hydroxy Compounds ◽  
Related Compounds ◽  
Unchanged Form

A description is given of a new method for the isolation from spruce meal of lignin in apparently a relatively unchanged form. The method consists in first extracting the spruce meal with a mixture of equal volumes of benzene and alcohol, followed by an extraction with water. The dried meal is then digested for 6–8 hr. at 110 °C. with 8–10 times its weight of ethylene glycol containing 0.2% of iodine, calculated on the weight of spruce meal taken. The reaction mixture is filtered, and the lignin isolated by pouring the filtrate into a large excess of cold water. Other catalysts such as hydrochloric acid may be used in place of iodine and the glycol may be replaced by a variety of hydroxy-compounds such as glycol mono-ethyl ether, glycerol, chlorhydrins, hydroxyacids, etc.

STUDIES ON LIGNIN AND RELATED COMPOUNDS: XXVIII. THE BEHAVIOR OF LIGNIN TOWARDS ACTIVATED HYDROGEN

1936 ◽  
Vol 14b (11) ◽  
pp. 404-407 ◽  
Author(s):  
R. G. D. Moore ◽  
Harold Hibbert
Keyword(s):  
Low Temperatures ◽  
Open Chain ◽  
Wood Meal ◽  
Building Unit ◽  
Negative Results ◽  
Spruce Wood ◽  
Related Compounds

Methylated methanol lignin prepared from fully methylated spruce wood-meal was subjected, at relatively low temperatures and pressures, to the action of hydrogen in the presence of catalysts, and under conditions such that reduction of open-chain ethylenic linkages readily occurs. Entirely negative results were obtained. This pointed to the absence of ethylenic linkages in the lignin building unit.

A STUDY OF THE MECHANISM AND KINETICS OF THE SULPHITE PROCESS

1939 ◽  
Vol 17b (4) ◽  
pp. 121-132 ◽  
Author(s):  
J. M. Calhoun ◽  
F. H. Yorston ◽  
O. Maass
Keyword(s):  
Temperature Coefficient ◽  
Arrhenius Equation ◽  
Practical Interest ◽  
Effect Of Temperature ◽  
Wood Meal ◽  
Spruce Wood ◽  
Mechanism And Kinetics ◽  
Kinetics Of

The rate of delignification of resin extracted spruce wood-meal has been determined in calcium-base sulphite liquor at temperatures from 130 °C. down to 50 °C. No break was found in the temperature coefficient curve at the lower temperatures, the reaction following the Arrhenius equation closely. Possible mechanisms of the reaction are discussed in the light of existing theories, and the effect of temperature on the yield of pulp is pointed out for its practical interest.

The Interrelationship between ECF Volume and ECF Anion Composition in the Regulation of Sodium Excretion

1970 ◽  
Vol 39 (4) ◽  
pp. 475-487
Author(s):  
J. J. Cohen ◽  
J. A. Chazan ◽  
S. Garella
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Bicarbonate ◽  
Sodium Excretion ◽  
Extracellular Fluid ◽  
Progressive Increase ◽  
Fluid Volume ◽  
Extracellular Fluid Volume ◽  
Volume Depletion ◽  
Anion Composition ◽  
Bicarbonate Infusion

1. The interrelationship between extracellular fluid volume and extracellular anion composition as determinants of sodium excretion was studied in thirty-four dogs. In six, hypovolaemia, hypochloraemia and hyperbicarbonataemia were induced by the administration of ethacrynic acid and a low chloride diet. Isotonic sodium bicarbonate was then infused resulting in a progressive increase in sodium excretion. After 3 h while continuing the sodium bicarbonate infusion, an infusion of hydrochloric acid was given in order to return extracellular anion composition towards normal. This resulted in a prompt fall in sodium excretion without a change in GFR. 2. Ten studies were performed to determine whether this hydrochloric acid-induced enhancement of sodium conservation depends upon the presence of volume depletion and sodium avidity or whether it could also be demonstrated under circumstances of volume expansion. In these studies, hypervolaemia, hypochloraemia, hyperbicarbonataemia and a brisk natriuresis were induced by infusing isotonic sodium bicarbonate into normal dogs. The addition of hydrochloric acid returned anion composition to normal and, as before, resulted in a prompt suppression of sodium excretion despite continued sodium loading and enhanced glomerular filtration. 3. Results obtained from three related protocols (six animals each) confirmed that hypochloraemia and hyperbicarbonataemia were the necessary prerequisite conditions for this effect of hydrochloric acid in volume expanded animals. We interpret these findings as evidence that the response of the kidney to changes in extracellular fluid volume may be significantly affected by changes in the extracellular concentration of physiologic anions.

Pyrimidine Derivatives and Related Compounds, V Synthesis of Some Isoxazolo [2,3-a] pyrimidines. A New Ring System

1977 ◽  
Vol 32 (3) ◽  
pp. 311-314 ◽  
Author(s):  
Mohamed Hilmy Elnagdi ◽  
Ezzat Mohamed Kandeel ◽  
Kamal Usef Sadek
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Ethyl Acetoacetate ◽  
Pyrimidine Derivative ◽  
Ring System ◽  
The Other ◽  
Acid Mixture ◽  
Pyrimidine Derivatives ◽  
Benzoyl Isothiocyanates ◽  
Related Compounds

3-Amino-5-phenyl-4-phenylazoisoxazole (1) reacts with ethyl acetoacetate to yield the corresponding ethyl isoxazolylaminocrotonate derivative (2) which could be thermally cyclized into the isoxazolopyrimidine derivative (4). On the other hand, condensation of 1 with ethoxymethylenemalononitrile has resulted in the formation of the aminoethylene derivative (5).Compound 1 reacted with acrylonitrile to yield the isoxazolo[2,3-a]pyrimidine derivative (6). The latter was converted into the corresponding exo derivative (8) by the action of acetic acid-hydrochloric acid mixture.Compound 1 also reacted with methoxycarbonyl-, ethoxycarbomyl- and benzoyl isothiocyanates to yield the isoxazolylthioureas (10a, b) and (11), respectively. The reaction of 2 with acetic acid-hydrochloric acid and with phenylhydrazine is reported.

Alkaloids of the Australian Rutaceae: Melicope fareana. IV. Some Reactions of 1-Methyl-4-quinolone-3-carboxyic Acid, a Degradation Product of the Alkaloids

1949 ◽  
Vol 2 (2) ◽  
pp. 272 ◽  
Author(s):  
JR Price
Keyword(s):  
Nitric Acid ◽  
Carboxylic Acid ◽  
Hydrochloric Acid ◽  
Degradation Product ◽  
Carboxyl Groups ◽  
Methyl Groups ◽  
Derivatives Of

Melicopine, melicopidine, and melicopicine are each oxidized by nitric acid to the same acid, C11H9O3N. Decarboxylation gives 1-methyl-4-quinolone (I) and the acid is shown to be 1-methyl-4-quinolone-3-carboxylic acid (II). The 3- and 6- mononitro-, 3,6-dinitro-, and 2-hydroxy-3,6-dinitro- derivatives of 1-methyl-4-quinolone have been prepared and the orientation of the substituents established by oxidation of the hydroxydinitro- compound to 5-nitro-N-methylanthranilic acid. 1-Methy1-4-quinolone-3-carboxylic acid is readily converted to a tetrahydro- derivative. The carboxyl groups in II and in the tetrahydro- acid are reduced by zinc and hydrochloric acid to methyl groups.

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