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.

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.

Notizen: Synthese strukturisomerer Dihydroxiderivate von Dibenzo-18-krone-6/Synthesis of Isomeric Dihydroxy Derivatives of Dibenzo-18-crown-6

1984 ◽  
Vol 39 (4) ◽  
pp. 542-544 ◽  
Author(s):  
Bernd Rieckemann ◽  
Klaus-B. Ebhardt ◽  
Fritz Umland
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Ethylene Glycol ◽  
Catalytic Reduction ◽  
Monomethyl Ether ◽  
Diazonium Salts ◽  
Ethylene Glycol Monomethyl Ether ◽  
Glycol Monomethyl Ether ◽  
Dilute Sulfuric Acid ◽  
Derivatives Of

In 1967 Pedersen described dibenzo-18-crown-6 (1) [1]. We report the preparation of its isomeric dihydroxy derivatives 2c and 3c. Nitration of 1 in acetic acid and chloroform yields the dinitro compounds 2a and 3a. 2a and 3a have different solubility in ethylene glycol monomethyl ether and can be separated [4]. Catalytic reduction of the dinitro derivatives with hydrazine and Raney nickel leads to the diamines 2b and 3b. The diazonium salts of 2b and 3 b are heated in dilute sulfuric acid and yield the phenols 2c and 3c.

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

The Phthalimidomethyl Rearrangement

1990 ◽  
Vol 43 (11) ◽  
pp. 1817 ◽  
Author(s):  
JFK Wilshire
Keyword(s):  
Sulfuric Acid ◽  
Nitrogen Atom ◽  
Carbon Atom ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Hindered Rotation ◽  
Initial Location ◽  
Concentrated Sulfuric Acid ◽  
Derivatives Of

The discovery of a new acid-catalysed monodentate N → C aromatic rearrangement, namely the phthalimidomethyl rearrangement, is reported. In this rearrangement, discovered during the reaction of N-hydroxymethylphthalimide with certain alkyl N-(4-nitrophenyl)carbamates in concentrated sulfuric acid solution, the phthalimidomethyl group migrates from its initial location on the nitrogen atom of the carbamate function to a carbon atom of the nitrophenyl group. Evidence, provided by an appropriate 'crossover' experiment, indicates that the rearrangement is intermolecular. Hindered rotation about the N(carbamoyl)-aryl bond of the N-phthalimidomethyl derivatives of both ethyl and methyl N-(2,4-dinitrophenyl)carbamate is reported.

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.

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.

Gallium Arsenide Integrated Circuits Decapsulation Technique Using Mixed Acid Chemistry For Die-Level Failure Analysis

2018 ◽  
Author(s):  
Harold Jeffrey M. Consigo ◽  
Ricardo S. Calanog ◽  
Melissa O. Caseria
Keyword(s):  
Gallium Arsenide ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
Mixed Acid ◽  
Optimum Parameters ◽  
Plastic Package ◽  
Fuming Nitric Acid ◽  
Concentrated Sulfuric Acid

Abstract Gallium Arsenide (GaAs) integrated circuits have become popular these days with superior speed/power products that permit the development of systems that otherwise would have made it impossible or impractical to construct using silicon semiconductors. However, failure analysis remains to be very challenging as GaAs material is easily dissolved when it is reacted with fuming nitric acid used during standard decapsulation process. By utilizing enhanced chemical decapsulation technique with mixture of fuming nitric acid and concentrated sulfuric acid at a low temperature backed with statistical analysis, successful plastic package decapsulation happens to be reproducible mainly for die level failure analysis purposes. The paper aims to develop a chemical decapsulation process with optimum parameters needed to successfully decapsulate plastic molded GaAs integrated circuits for die level failure analysis.

PRODUCTION OF SULFOCATIONITE BY MODIFICATION OF NATURAL COAL WITH CONCENTRATED SULFURIC ACID

2020 ◽  
Vol 3 (441) ◽  
pp. 104-109
Author(s):  
N.A. Bektenov ◽  
◽  
N.C. Murzakassymova ◽  
M.A. Gavrilenko ◽  
А.N. Nurlybayeva ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Concentrated Sulfuric Acid ◽  
Natural Coal
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