Methylation of polymethylbenzenesulfonic acids by hexamethylbenzene and pentamethylbenzenesulfonic acid in concentrated sulfuric acid

1988 ◽  
Vol 66 (1) ◽  
pp. 162-167 ◽  
Author(s):  
Hans Cerfontain ◽  
Ankie Koeberg-Telder
Keyword(s):  
Sulfuric Acid ◽  
Sulfonic Acid ◽  
Sulfonic Acids ◽  
Substrate Reactivity ◽  
Concentrated Sulfuric Acid

The methylation of a series of polymethylbenzenes (PoMB's) or their sulfonic acids by added hexamethylbenzene (HMB) and pentamethylbenzene-1-sulfonic acid (PeMB-1-S) as reagents in 95.5 and 98.4% H2SO4 as solvent has been studied under homogeneous conditions. HMB effects methylation of 2,4,6-trimethylbenzene-1-sulfonic acid (2,4,6-TrMB-1-S), 2,3,4,6-tetramethylbenzene-1-sulfonic acid (2,3,4,6-TeMB-1-S), and 2,3,5,6-TeMB-1-S, but not of the sulfonic acids of 1,3-dimethylbenzene (1,3-DMB), 1,2,3-TrMB, 1,2,4-TrMB, and 1,2,3,4-TeMB. PeMB-1-S is less reactive as methylating reagent than HMB. The observed substrate reactivity towards methylation by HMB was observed to decrease in the order [Formula: see text], and towards methylation by PeMB-1-S to decrease in the order [Formula: see text]. On the basis of a comparison of these orders of substrate reactivities with those predicted for the series of the PoMB-1-sulfonates and the corresponding PoMB's, it is concluded that the substrate species undergoing methylation are the PoMB's and not the corresponding sulfonates.

ChemInform Abstract: Equilibria and Nitration of Sulfonic Acids in Concentrated Sulfuric Acid

ChemInform ◽  
2010 ◽  
Vol 23 (2) ◽  
pp. no-no
Author(s):  
N. C. MARZIANO ◽  
A. TOMASIN ◽  
C. TORTATO
Keyword(s):  
Sulfuric Acid ◽  
Sulfonic Acids ◽  
Concentrated Sulfuric Acid

Mechanism of Sulfonation of 4-Hydroxyazobenzene

1971 ◽  
Vol 49 (1) ◽  
pp. 152-156 ◽  
Author(s):  
E. Buncel ◽  
W. M. J. Strachan ◽  
H. Cerfontain
Keyword(s):  
Sulfuric Acid ◽  
Complex Formation ◽  
Sulfonic Acid ◽  
Acid Media ◽  
Proton Abstraction ◽  
Rate Determining Step ◽  
Concentrated Sulfuric Acid

The mechanism of sulfonation of 4-hydroxyazobenzene and of 4-hydroxyazobenzene-4′-sulfonic acid in concentrated sulfuric acid media is examined through rate correlations and comparison is drawn with sulfonation of alkyl- and halogenobenzenes by means of [Formula: see text] plots. It is concluded that several mechanisms are operative in the hydroxyazobenzene system and that the curvature of the plot is the result of a change in rate-determining step from σ-complex formation to proton abstraction.

Meso and β-pyrrole sulfonated porphyrins obtained by sulfonation of 5,15-bis(phenyl)porphyrin

2000 ◽  
Vol 04 (05) ◽  
pp. 564-568 ◽  
Author(s):  
HECTOR GARCIA-ORTEGA ◽  
JOSEP M. RIBO
Keyword(s):  
Sulfuric Acid ◽  
Sodium Salt ◽  
Good Yield ◽  
Sulfonic Acid ◽  
Disulfonic Acid ◽  
Acid Mixture ◽  
Sodium Salts ◽  
Concentrated Sulfuric Acid ◽  
Trisodium Salt

The sulfonation of 5,15-bis(phenyl)porphyrin (DPP) in concentrated sulfuric acid results in substitution on the β-pyrrolic positions and the expected sulfonation on the para positions of the phenyl substituents. The sodium salt of 5,15-bis(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( S 3 DPP ) was prepared in good yield, the sodium salts of 5,15-bis(4-sulfonatophenyl)porphyrin ( S 2 A DPP ), 5-phenyl-15-(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( S 2 B DPP ) and 15-phenyl-5-(4-sulfonatophenyl)porphyrin ( S 1 A DPP ) were isolated, and 5,15-bis(phenyl)porphyrin-2-sulfonic acid ( S 1 B DPP ) was detected in a mixture with S 1 A DPP . The β-pyrrole sulfonato substituents are stable and their potential synthetic use is shown by the preparation of the trisodium salt of 10-bromo-5,15-bis(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( BrS 3 DPP ) by NBS bromination of S 3 DPP . In a methanol/sulfuric acid mixture the sulfonation occurs on the meso positions, and the tetrasodium salt of 10,20-bis (4-sulfonatophenyl)porphyrin-5,15-disulfonic acid ( S 4 DPP ) was obtained.

Synthesis of methylal from methanol and formaldehyde catalyzed by Brønsted acid ionic liquids with different alkyl groups

RSC Advances ◽  
2015 ◽  
Vol 5 (106) ◽  
pp. 87200-87205 ◽  
Author(s):  
Jiahan Sun ◽  
Hansheng Li ◽  
Haoran Song ◽  
Qin Wu ◽  
Yun Zhao ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Catalytic Activity ◽  
Sulfuric Acid ◽  
Sulfonic Acid ◽  
Carbon Chain ◽  
Catalytic Performance ◽  
Carbon Chain Length ◽  
Alkyl Groups ◽  
Toluene Sulfonic Acid ◽  
Concentrated Sulfuric Acid

The carbon chain length of ILs has an effect on its catalytic activity. The ionic liquid of [C6ImBS][HSO4] shows the best catalytic performance which is near that of concentrated sulfuric acid and p-toluene sulfonic acid.

Preparation and Catalytic Performances of Glucose Char Sulfonic Acids

2011 ◽  
Vol 236-238 ◽  
pp. 112-115 ◽  
Author(s):  
Qiong Xu ◽  
Du Lin Yin ◽  
Yue Xia
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Sulfonic Acid ◽  
Good Activity ◽  
Sulfonic Acids ◽  
Step Procedure ◽  
Acid Loading ◽  
Catalytic Performances

A series of glucose char sulfonic acids (GCSA) were prepared via a two-step procedure involving sulfuric acid catalytic charring of glucose and successively sulfonation. GCSA prepared in this new route possess high sulfonic acid loading, and acid capacity of GCSA-2 reaches as high as 2.60 mmol g-1 at charring conditions of sulfuric acid being 80%, ratio of glucose and sulfuric acid being 1:8, charring time being 3 h, charring temperature being 80 °C. All GCSA were found to be active in the esterification between n-butanol and acetic acid. GCSA-2 behaved with good activity with 95.6% conversion and 100% ester selectivity.

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

Addition of primary alcohols to 3-chlorononafluoro-1,5-hexadiene and perfluoro-1,3,5-hexatriene

1985 ◽  
Vol 50 (8) ◽  
pp. 1714-1726 ◽  
Author(s):  
Václav Dědek ◽  
Igor Linhart ◽  
Milan Kováč
Keyword(s):  
Sulfuric Acid ◽  
Primary Alcohols ◽  
Principal Product ◽  
Allyl Rearrangement ◽  
Concentrated Sulfuric Acid ◽  
Sodium Alkoxide

Sodium alkoxide-catalyzed addition of methanol, ethanol and propanol to 3-chlorononafluoro-1,5-hexadiene (I) proceeds at temperatures -35 °C to 8 °C with allyl rearrangement, affording 1,6-dialkoxy-1,1,2,3,4,4,5,6,6-octafluoro-2,4-hexadiene (V) as the principal product, along with 1,6-dialkoxy-1,2,3,3,4,5,6,6-octafluoro-1,5-diene (VI) and trans-1,6-dialkoxy-1,1,2,3,4,4,5,6,6-nonafluoro-2-hexene (VII). The ethers Va-Vc consist of the cis,trans- and trans,trans-isomers in about 3 : 1 ratio, whereas the ethers VIa-VIc have trans,trans-configuration. Ethers Vc and VIc react with concentrated sulfuric acid to give dipropyl 2,3,4,5-tetrafluoro-2,4-hexadienedioate (IX) and dipropyl 2,3,4,4,5-pentafluoro-2-hexenedioate (X), respectively, whereas the ether VIIc affords a mixture of propyl 6-propyloxy-2,3,4,4,5,6-heptafluoro-2-hexenoate (XI) and ester X. Addition of methanol to perfluoro-1,3,5-hexatriene (II) affords 1,1,2,3,4,5,6,6-octafluoro-1,6-dimethoxy-3-hexene (XIII) as the principal product.

scholarly journals 4,5,6-Trichloropyrimidine-2-carboxamide

Molbank ◽  
10.3390/m1190 ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. M1190
Author(s):  
Andreas S. Kalogirou ◽  
Panayiotis A. Koutentis
Keyword(s):  
Sulfuric Acid ◽  
Elemental Analysis ◽  
Maldi Tof ◽  
Concentrated Sulfuric Acid

Reaction of 4,5,6-trichloropyrimidine-2-carbonitrile (1) with concentrated sulfuric acid at ca. 20 °C gave 4,5,6-trichloropyrimidine-2-carboxamide (5) in 91% yield. The new compound was fully characterized by IR, MALDI-TOF, NMR and elemental analysis.

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