Mechanism of the interaction of concentrated sulfuric acid and glacial acetic acid

1969 ◽  
Vol 18 (6) ◽  
pp. 1217-1219 ◽  
Author(s):  
A. V. Kotov ◽  
V. A. Zarinskii ◽  
V. M. Bokina
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Glacial Acetic Acid ◽  
Concentrated Sulfuric Acid

Bromination of Acridine

2018 ◽  
Vol 71 (4) ◽  
pp. 285
Author(s):  
Graham S. Chandler ◽  
Wolfgang H. F. Sasse
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Quantitative Determination ◽  
Glacial Acetic Acid ◽  
Tiny Amount ◽  
Concentrated Sulfuric Acid

The quantitative determination of the products of bromination of acridine in concentrated sulfuric acid and glacial acetic acid is described. In both cases, the only monobromo products were the 2- and 4-substituted compounds. With sulfuric acid, the 4-isomer predominates whereas in acetic acid, the 2-isomer is predominant. This work expands substantially on the tiny amount of previous work on halogenation of dibenzo-annelated pyridines.

Rapid Semimicro Procedure for Estimating Free and Total Cholesterol

1959 ◽  
Vol 5 (6) ◽  
pp. 609-614 ◽  
Author(s):  
Armand J Courchaine ◽  
William H Miller ◽  
Donald B Stein
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Total Cholesterol ◽  
Glacial Acetic Acid ◽  
Heat Of Reaction ◽  
Rapid Procedure ◽  
Color Development ◽  
Concentrated Sulfuric Acid ◽  
The Stability

Abstract A rapid procedure for the determination of both free and total cholesterol in serum is described. The color development is extremely rapid, and once fully developed the color remains stable for several hours. The heat of reaction produced by the combination of concentrated sulfuric acid, phosphoricacid, and glacial acetic acid is apparently responsible for the rapid color development. The stable ferric chloride reagent containingphosphoric acid appears to be the contributing factor to the stability of the color. The results obtained with this procedure compare favorably with those obtained with saponification methods.

Synthèse de quelques dérivés du tétrahydro-4,5,6,7 benzothiazoline-Δ2α-acétate d'éthyle

1968 ◽  
Vol 46 (23) ◽  
pp. 3643-3648 ◽  
Author(s):  
Réal Laliberté ◽  
Hilda Warwick ◽  
Georges Médawar
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Spectroscopic Evidence ◽  
Concentrated Sulfuric Acid ◽  
Derivatives Of

Some derivatives of α-cyano tétrahydro benzothiazoline-Δ2α-acetic acid and their intermediates are described. The lack of reactivity of this class of compounds and products of treatment with concentrated sulfuric acid have been studied. Assignment of configuration was based on infrared and ultraviolet spectroscopic evidence.

Standard of Purity for Cholesterol

1963 ◽  
Vol 9 (2) ◽  
pp. 121-134 ◽  
Author(s):  
Nathan Radin ◽  
Adalbert L Gramza
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Ethyl Alcohol ◽  
Spectral Region ◽  
Glacial Acetic Acid ◽  
Absolute Ethyl Alcohol ◽  
The Third ◽  
Derivative Method ◽  
Ultraviolet Spectral Region ◽  
Lower Limits

Abstract Three recrystallization technics were used to fractionate five commercial cholesterol products and one artificial mixture. One technic involved the recrystallization of cholesterol from absolute ethyl alcohol, the second technic involved the recrystallization of cholesterol from glacial acetic acid, and the third technic used the dibromide derivative method. The molar absorptivities for the various crystal batches were in the range of 1610 to 1750 L. mole-1 cm.-1 at 620 mµ with a modified Liebermann-Burchard procedure. The molar absorptivities were in the range of 9,800 to 11,500 L. mole-1 cm.-1 at 560 mµ with a modified sulfuric acid-iron method. The original products and the ethyl alcohol recrystallized products showed molar absorptivities at the lower limits of the ranges, while the glacial acetic acid and dibromide derivative recrystallized cholesterol showed molar absorptivities at the higher limits of the ranges. Absorption peaks at 235 mµ for methyl alcohol solutions of the cholesterol preparations were used to estimate cholesterol impurities on the basis of 7-keto cholesterol acetate absorption values. The decrease of absorption in the ultraviolet spectral region established that impurities were removed from the cholesterol preparations studied.

scholarly journals Rearrangements in the acid-catalyzed formation of lactones from 2-hydroxynorbornane-2-acetic acid derivatives and related compounds

1992 ◽  
Vol 70 (9) ◽  
pp. 2491-2501 ◽  
Author(s):  
Peter Yates ◽  
Magdy Kaldas
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Ethyl Esters ◽  
Alkyl Groups ◽  
Acid Lactone ◽  
Concentrated Sulfuric Acid ◽  
Acid Catalyzed ◽  
Preliminary Study ◽  
Related Compounds ◽  
Acetic Acids

A mixture of the epimeric ethyl 2-hydroxynorbornane-2-acetates (1) on treatment with concentrated sulfuric acid is converted in turn to the lactones of exo-2-hydroxynorbornane-1-acetic acid (4), endo-6-hydroxynorbornane-endo-2-acetic acid (5), and exo-3-hydroxynorbornane-exo-2-acetic acid (6). With trifluoroacetic acid or 50% sulfuric acid, 1 gives 4, but this does not react further. In concentrated sulfuric acid the parent acids of 1 (7) and (E)- and (Z)-(norborn-2-ylidene)acetic acids (8 and 9) and their ethyl esters (10 and 11) give 6 as the infinity product. A mixture of 5-norbornene-endo- and exo-2-acetic acid (30 and 31) on treatment with 50% sulfuric acid gives 4, 5, 6, and exo-2-hydroxynorbornane-syn-7-acetic acid lactone (33). Routes are proposed for the formation of the lactones that involve protonation and carbocation formation followed by rearrangement via Wagner–Meerwein, endo-6,2-hydride, and exo-3,2-hydride shifts in decreasing order of preference. It is postulated that the usual inhibition of the rearrangement of tertiary to secondary norbornyl carbocations is not operative when the third substituent is a carboxymethyl group or its derivatives because of the electron-withdrawing properties of such groups relative to simple alkyl groups. A preliminary study has shown that exo-5-acetyloxy-endo-2-hydroxynorbornane-exo-2-acetic acid (35) with 50% sulfuric acid gives four products that are considered to be the γ-lactones of endo-5-acetyloxy- and endo-5-hydroxynorbornane-1-acetic acid (38 and 39) and exo-2-acetyloxy-1-hydroxy-and 1,2-dihydroxynorbornane-syn-7-acetic acid (40 and 41). Protonation of either the hydroxyl or acetyloxyl group is postulated, giving two carbocations that undergo rearrangements as in the case of 1, together with 3,2-hydroxyl shifts. The structures of the lactones are assigned on the basis of spectroscopy, reactivity, and analogy. The reactions of the lactones, which lead to a variety of hydroxy- and oxonorbornaneacetic acids, illustrate their synthetic potential.

scholarly journals Comparative study of the performance of acetylated bamboo with different catalysts

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 44-58
Author(s):  
Saisai Huang ◽  
Zhongqing Ma ◽  
Yujing Nie ◽  
Fengzhu Lu ◽  
Lingfei Ma
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Dimensional Stability ◽  
Color Change ◽  
Potassium Acetate ◽  
Color Difference ◽  
Phyllostachys Pubescens ◽  
Oh Groups ◽  
Weight Percentage ◽  
Concentrated Sulfuric Acid

The catalytic acetylation of bamboo (Phyllostachys pubescens) was compared with acetylation using concentrated sulfuric acid, acetic acid, potassium acetate, and noncatalytic acetylation at 120 °C for 3 h. The weight percentage gain, dimensional stability, color difference, and wettability of bamboo after the acetylation was comprehensively measured. Also, the chemical and thermal properties of the resultant bamboo were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) analysis. The results showed that the potassium acetate-catalyzed acetylation of bamboo greatly accelerated the reaction degree, had little effect on color change, extraordinarily decreased wettability, and had little irregular impact on the dimensional stability. The catalytic activity was followed by potassium acetate, sulfuric acid, noncatalytic acid, and acetic acid. The FTIR analysis showed that the functional groups in the acetylated bamboo were mainly affected by different catalysts. The thermal stability of acetylated bamboo was higher than the untreated bamboo. In particular, potassium acetate-catalytic acetylation greatly reacted with -OH groups and increased thermal decomposition.

ALTERATION IN HORMONAL ACTIVITY RESULTING FROM CHEMICAL TREATMENT OF BEEF GROWTH HORMONE

1960 ◽  
Vol XXXIII (I) ◽  
pp. 1-9
Author(s):  
Martin Sonenberg ◽  
William L. Money
Keyword(s):  
Growth Hormone ◽  
Acetic Acid ◽  
Biological Activity ◽  
Nitrous Acid ◽  
Glacial Acetic Acid ◽  
Thioglycolic Acid ◽  
Hormonal Activity ◽  
Reaction Conditions ◽  
Concentrated Sulfuric Acid ◽  
Growth Promoting

ABSTRACT The effect of various reagents, which produce protein derivatives, on the biological activity of growth hormone has been studied. Various conditions which affect growth hormone stability have also been investigated. In general, it has been found that reaction of growth hormone with phenylisocyanate, nitrous acid or concentrated sulfuric acid, under the conditions specified, destroyed the biological activity. Reaction of growth hormone with thioglycolic acid, iodine, or acid methanol yielded growth hormone derivatives which were active or inactive, depending on the reaction conditions. Reaction with acid ethanol, formaldehyde, cysteine, sodium bisulfite, diisopropylfluorophosphate, urea or bromine had no effect on the growth-promoting activity of these preparations. Growth hormone was found to be rather stable in dilute and glacial acetic acid except when heated to a temperature of 94° C. The implications of these findings are discussed. None of the growth hormone derivatives obtained in this study was able to inhibit the growth-promoting response induced by unmodified growth hormone preparations.

scholarly journals HISTOCHEMICAL ACYLATION OF ALDEHYDES PRODUCED BY PERIODIC ACID OXIDATION

1966 ◽  
Vol 14 (7) ◽  
pp. 529-537 ◽  
Author(s):  
R. D. LILLIE
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Acetic Anhydride ◽  
Glacial Acetic Acid ◽  
Periodic Acid ◽  
Potassium Hydroxide Solution ◽  
Acid Oxidation ◽  
Enol Acetate ◽  
Periodic Acid Oxidation ◽  
Schiff Reaction

Aldehydes produced in tissue sections by periodic acid oxidation are readily acetylated or benzoylated so as to weaken or completely prevent the Schiff and other chromogenic reactions. The reactivity of acylated aldehydes to Schiff reagent is promptly restored by saponification in alcoholic potassium hydroxide solution (10-20 min, 1% KOH, 70% ethanol). Benzoylation with 5-10% benzoyl chloride in pyridine gave the promptest, most complete and consistent aldehyde blockade, which was somewhat inferior on addition of 0.5% sulfuric acid. Pyridine acetic anhydride mixtures, 25, 40 and 50% gave partial to complete blockade. Addition of 0.25-0.5% sulfuric acid did not give consistent effects. Acetic anhydride at 60°C gave partial blockade at ½-5 hr, on addition of 0.01-0.25% sulfuric acid total or subtotal blockade was achieved. Acetylation in alcohol gave inferior resutlts. Use of 25% acetic anhydride ims glacial acetic acid gave inferior results; addition of 0.25% sulfuric acid produced total to subtotal blockade at 4-5 hr. Glacial acetic acid was without appreciable blockade effect. Sulfation in 10% and 25% H2SO4/glacial acetic acid failed to blockade aldehydes. Experiments with the peracetic acid Schiff reaction for ethylene groups indicate that some proportion of enol monobenzoate may be formed, and that with the various acetylation techniques a smaller or negligible proportion of enol acetate is formed. Acetic anhydride with 0.25% H2S04 at 60° appears to form only aldehyde diacetate. Experiments with the bromination silver techniques did not give satisfactory results.

Sign in / Sign up

Export Citation Format

Share Document