Reactions of Benzenesulfonohydrazides and Benzenesulfonamides with Hydrogen Chloride or Hydrogen Bromide in Acetic Acid

1977 ◽  
Vol 66 (7) ◽  
pp. 1009-1012 ◽  
Author(s):  
D.K. Yung ◽  
T.P. Forrest ◽  
A.R. Manzer ◽  
M.L. Gilroy
Keyword(s):  
Acetic Acid ◽  
Hydrogen Chloride ◽  
Hydrogen Bromide

scholarly journals Fast-Hardening Foam: Fire and Explosion Prevention at Facilities with Hazardous Chemicals

2017 ◽  
Vol 6 (4) ◽  
pp. 56
Author(s):  
Gennady N. Kuprin ◽  
Denis S. Kuprin
Keyword(s):  
Acetic Acid ◽  
Hydrogen Chloride ◽  
Hydrogen Fluoride ◽  
Diesel Fuel ◽  
High Probability ◽  
Hydrogen Bromide ◽  
Screening Method ◽  
Hazardous Chemicals ◽  
Experimental Apparatus ◽  
Fire And Explosion

Analysis of the terroristic attacks in Siria, Afghanistan and other countries has shown high probability of the hazardous chemicals application by the terroristic groups. In the article the most catastrophic accidents which were connected with hazardous chemicals are described.That is why research and developments in the sphere of protection from hazardous chemicals are still actual.This article is dedicated to the new screening method of the spilled hazardous chemicals surface on the example of protection of the factories with these substances. Methodology, experimental apparatus, protective fast-hardening foam features, names of hazardous chemicals are shown.Test were made for such chemicals as: acetic acid, acetone, ammonia, bromine, chlorbenzene, chloroform, hydrogen bromide, hydrogen chloride, hexane, hydrazine, diesel fuel, dichlorethane, kerosene, toluene, phenol, hydrogen fluoride. Fantastic results were achieved in terms of isolating capability of the fast-hardening foam against evaporations of the pointed substances.

Peptide syntheses with the 2,4,6-trimethylbenzyl esters of L-asparagine and L-glutamine

1967 ◽  
Vol 20 (2) ◽  
pp. 365 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Acetic Acid ◽  
Amino Acid ◽  
Hydrogen Chloride ◽  
Hydrogen Bromide ◽  
Amino Acid Esters ◽  
Mild Conditions ◽  
Acid Esters

The 2,4,6-trimethylbenzyl esters of L-asparagine and L-glutamine have been obtained as the crystalline hydrochlorides by treatment of the o- nitrophenylsulphenyl amino acid esters with methanolic hydrogen chloride. These hydrochlorides were used in the synthesis of several benzyloxycarbonyl peptide 2,4,6-trimethylbenzyl esters, which were converted into the corresponding free peptides by the action of hydrogen bromide in acetic acid under mild conditions.

The use of 2,4,6-trimethylbenzyl esters in peptide synthesis

1966 ◽  
Vol 19 (6) ◽  
pp. 1067 ◽  
Author(s):  
FHC Stewart
Keyword(s):  
Acetic Acid ◽  
Hydrogen Chloride ◽  
Peptide Synthesis ◽  
Hydrogen Bromide ◽  
Ester Group ◽  
Protecting Groups ◽  
Reaction Conditions ◽  
Model Experiments ◽  
Benzyl Esters

Model experiments with the 2,4,6-trimethylbenzyl esters of N-acylamino acids have shown that this ester group is cleaved by hydrogen bromide in acetic acid under reaction conditions which do not affect benzyl esters appreciably, but which result in removal of benzyloxycarbonyl amino-protecting groups. 2,4,6-Trimethyl- benzyl esters, however, are unaffected by methanolic hydrogen chloride under the conditions used to cleave o-nitrophenylsulphenyl and trityl protecting groups. These selective differences have been utilized for the synthesis of various benzyloxycarbonyl peptide 2,4,6-trimethylbenzyl esters up to the hexapeptide level. Some of these derivatives have been converted into the corresponding free peptides by the action of hydrogen bromide in acetic acid. The 2,4,6-trimethylbenzyl group is more readily cleaved by hydrogen bromide than p-nitrobenzyloxycarbonyl and the possible application of this situation to peptide synthesis is considered.

Cyclohexane compounds. VII. Nucleophilic scission of the stereoisomeric 3-methoxycyclohexene oxides

1968 ◽  
Vol 46 (1) ◽  
pp. 35-42 ◽  
Author(s):  
R. A. B. Bannard ◽  
A. A. Casselman ◽  
E. J. Langstaff ◽  
R. Y. Moir
Keyword(s):  
Acetic Acid ◽  
Hydrogen Chloride ◽  
Vapor Phase ◽  
Inductive Effect ◽  
Hydrogen Bromide ◽  
Transition States ◽  
Product Distributions ◽  
Steric Factors ◽  
Alkaline Conditions ◽  
Cis And Trans

The mode of scission of cis- and trans-3-methoxycyclohexene oxides by hydrogen chloride, hydrogen bromide, ammonia, acetic acid, and methanol (under both acidic and alkaline conditions) has been examined using vapor-phase chromatography to detect and isolate minor isomers. Approximately 10% of the product from opening of the trans oxide is formed by attack at position-2 with each of these nucleophiles, whereas opening of the cis oxide proceeds exclusively by attack at position-1. The results are interpreted as reflecting very similar transition states for all of these reactions, with differences in product distributions for the two oxides being governed by the inductive effect of the methoxyl group and by steric factors in the corresponding transition states.

The synthesis of norbornanes with functionalized carbon substituents at a bridgehead. 1-(3-Oxonorborn-1-yl)ethanone and 1-(3-oxonorborn-1-yl)-2-propanone

1992 ◽  
Vol 70 (5) ◽  
pp. 1492-1505 ◽  
Author(s):  
Peter Yates ◽  
Magdy Kaldas
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Hydrogen Bromide ◽  
Tertiary Alcohol ◽  
Ethyl Bromoacetate ◽  
Second Molar ◽  
Molar Equivalent ◽  
Acid Lactone ◽  
Basic Hydrolysis ◽  
Hydrolysis Of

Treatment of 2-norobornene-1-carboxylic acid (7) with one equivalent of methyllithium in ether followed by a second molar equivalent after dilution with tetrahydrofuran gave 1-(norborn-2-en-lyl)ethanone (10) and only a trace of the tertiary alcohol 11. Reaction of 7 with formic acid followed by hydrolysis gave a 4:3 mixture of exo-3- and exo-2-hydroxynorbornane-1-carboxylic acid (16 and 17), whereas oxymercuration–demercuration gave only the exo-3-hydroxy isomer 16. Oxidation of 16 and 17 gave 3- and 2-oxonorbornane-1-carboxylic acid (27 and 29), respectively. Oxymercuration–demercuration of 10 gave exclusively 1-(exo-3-hydroxynorborn-1-yl)ethanone (30), which was also prepared by treatment of 16 with methyllithium in analogous fashion to that used for the conversion of 7 to 10. Oxidation of 30 gave 1-(3-oxonorborn-1-yl)ethanone (1). Dehydrobromination of exo-2-bromonorbornane-1-acetic acid and dehydration of 2-hydroxy-norbornane-2-acetic acid derivatives gave 1-(norborn-2-ylidene) acetic acid derivatives to the exclusion of norborn-2-ene-1 -acetic acid derivatives. Treatment of exo-5-acetyloxy-2-norobornanone (52) with ethyl bromoacetate and zinc gave ethyl exo-5-acetyloxy-2-hydroxynorbornane-(exo- and endo-2-acetate (53 and 54). Reaction of 53 with hydrogen bromide gave initially ethyl endo-3-acetyloxy-exo-6-bromonorbornane-1-acetate (59), which was subsequently converted to a mixture of 59 and its exo-3-acetyloxy epimer 61. Catalytic hydrogenation of this mixture gave a mixture of ethyl endo- and exo-3-acetyloxynorbornane-1 -acetate (62 and 63). Basic hydrolysis of this gave a mixture of the corresponding hydroxy acids, 70 and 71; the former was slowly converted to the latter at pH 5. Oxidation of the mixture of 70 and 71 gave 3-oxonorbornane-1-acetic acid (72). Treatment of the mixture with methyllithium as for 16 gave a mixture of 1-(endo- and exo-3-hydroxynorborn-1-yl)-2-propanone (73 and 74), which was oxidized to 1-(3-oxo-norborn-1-yl)-2-propanone (2). Reaction of exo-2-hydroxynorbornane-1-acetic acid lactone (75) with methyllithium in ether gave (1-(exo-2-hydroxynorborn-1-yl)-2-propanone (76), which on oxidation gave the 2-oxo isomer 78 of 2.

scholarly journals The Reaction of Derivatives of D-Xylal and D-Arabinal with Hydrogen Chloride and Hydrogen Bromide.

1969 ◽  
Vol 23 ◽  
pp. 2083-2094 ◽  
Author(s):  
Klaus Bock ◽  
Inge Lundt ◽  
Christian Pedersen ◽  
Tord Holme ◽  
Alf A. Lindberg ◽  
...  
Keyword(s):  
Hydrogen Chloride ◽  
Hydrogen Bromide ◽  
Derivatives Of
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