scholarly journals The reaction of thionyl chloride with methyl-substituted heteroaromatic compounds

1977 ◽  
Vol 30 (2) ◽  
pp. 433 ◽  
Author(s):  
M Davis ◽  
DB Scanlon
Keyword(s):  
Thionyl Chloride ◽  
Heterocyclic Ring ◽  
Methyl Group ◽  
Heteroaromatic Compounds

Some heteroaromatic compounds with methyl substituents in the heterocyclic ring, such as 2-methylbenzothiazole, 2-methylbenzoxazole, and analogues, undergo rapid methyl group chlorination when heated with thionyl chloride. A mechanism for such reactions is proposed.

Chemistry of Fenchonesulfonic Acid Derivatives

1995 ◽  
Vol 50 (2) ◽  
pp. 283-288 ◽  
Author(s):  
Gabriele Wagner ◽  
Uwe Verfürth ◽  
Rudolf Herrmann
Keyword(s):  
Acetic Anhydride ◽  
Thionyl Chloride ◽  
Sulfonic Acid ◽  
Reaction Rate ◽  
Enantiomeric Excess ◽  
Methyl Group ◽  
Close Analogy ◽  
Chiral Sulfoxides ◽  
Mndo Calculations ◽  
Nmr Techniques

(1 S) - (+)-Fenchone is sulfonated by SO3 or H2SO4/acetic anhydride in the bridgehead methyl group. This could be confirmed by NMR techniques (INADEQUATE). The fenchonesulfonic acid obtained is converted (SOCl2/NH3) to the cyclic fenchonesulfonimide, which can be oxidized to the corresponding oxaziridine, in close analogy to 10-camphorsulfonimide. Improved procedures for this reaction sequences are given. During the treatment of the sulfonic acid with thionyl chloride, a byproduct with a rearranged bicyclic skeleton is observed whose structure has been determined by ozonolytic degradation and NMR techniques. A possible mechanism for this rearrangement is suggested, based on MNDO calculations of the intermediate carbocations. The fenchonesulfonyloxaziridine oxidizes sulfides to chiral sulfoxides with appreciable enantiomeric excess, but very low reaction rate. A comparison with camphor-derived oxaziridines having similar steric requirements is made.

scholarly journals Synthesis of Novel 1,2,3-Triazole-Dihydropyrimidinone Hybrids Using Multicomponent 1,3-Dipolar Cycloaddition (Click)–Biginelli Reactions: Anticancer Activity

Synlett ◽  
2020 ◽  
Vol 31 (06) ◽  
pp. 615-621
Author(s):  
Elisabete P. Carreiro ◽  
Ana M. Sena ◽  
Adrián Puerta ◽  
José M. Padrón ◽  
Anthony J. Burke
Keyword(s):  
Breast Cancer ◽  
Lung Cancer ◽  
Heterocyclic Ring ◽  
Small Cell ◽  
Dipolar Cycloaddition ◽  
Cancer Cervix ◽  
Small Cell Lung ◽  
Methyl Group ◽  
Cancer Breast ◽  
Biginelli Reactions

In this work, 21 novel (1,4-disubstituted 1,2,3-triazole)-dihydropyrimidinone (1,2,3-trzl-DHPM) type hybrids were synthesized and characterized. These were divided into two types: hybrids A (5 in total) containing the dihydropyrimidinone heterocyclic ring decorated with a 1,4-disubstituted 1,2,3-triazole in the C-5 position [these compounds were accessed by a multicomponent copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) (or click)–Biginelli reactions with satisfactory yields (39–57%)] and hybrids B (16 in total) containing two 1,2,3-triazole units in the C-5 and C-6 methyl position of the DHPM. Hybrids B were synthesized via functionalization of the C-6 methyl group of hybrids A, a multistep sequence of reactions was used that included bromination, azidation, and a CuAAC. Hybrids B were obtained in very good to excellent yields (up to 99%). Some hybrids A and B were evaluated for their antiproliferative activity against different cancer cell lines that included A549 and SW1573 (non-small-cell lung), HBL-100 and T-47D (breast), HeLa (cervix) and WiDr (colon). Three of these hybrids were potent cell proliferation inhibitors of non-small-cell lung cancer, cervix cancer, breast cancer, and colon cancer.

scholarly journals The effect of heterocyclic S,S’-ligands on the electrochemical properties of some cobalt(III) complexes in acid

2005 ◽  
Vol 70 (1) ◽  
pp. 51-61
Author(s):  
Vladislava Jovanovic ◽  
K. Babic-Samardzija ◽  
Sofija Sovilj
Keyword(s):  
Cyclic Voltammetry ◽  
Anodic Polarization ◽  
Heterocyclic Ring ◽  
Mixed Ligand ◽  
Heterocyclic Amines ◽  
Piperidine Ring ◽  
Methyl Group ◽  
Inhibiting Effect ◽  
Hydrogen Evolution Reactions ◽  
Cyclic Voltammetry Data

Eight mixed-ligand cobalt(III) complexes with the macrocyclic amine 1,4,8,11-tetraazacyclotetradecane (cyclam) and a heterocyclic dithiocarbamate (Rdtc-)i.e., morpholine-(Morphdtc), thiomorpholine- (Timdtc), piperazine-(Pzdtc), N-methylpiperazine-(Mepzdtc), piperidine- (Pipdtc), 2-, 3- or 4-methylpiperidine-(2-, 3- and 4-Mepipdtc) carbodithionato-S,S ions, of the general formula [Co(cyclam)Rdtc](ClO4)2, were investigated in deoxygenated 0.1 MHClO4 solutions. Cyclic voltammetry data at a glassy carbon (GC) electrode demonstrate a redox reaction of cobalt(III) from the complexes at potentials strongly influenced by the presence of different heterocyclic Rdtc- ligands. In this respect, the complexes were separated into two groups: the first, with a heteroatom O, S or N in the heterocyclic ring, and the second, with a methyl group on the piperidine ring of the Rdtc- ligand. Anodic polarization of an Fe electrode in the presence of the complexes shows their influence not only on the dissolution of iron but also on the hydrogen evolution reactions and on this basis complexes the complexes could be divided into the same two groups. It was found that the weaker the inhibiting effect of the free heterocyclic amines is, the significantly higher is the efficiency of the corresponding complexes.

scholarly journals Microbial metabolism of pyridinium compounds. Radioisotope studies of the metabolic fate of 4-carboxy-1-methylpyridinium chloride

1972 ◽  
Vol 128 (3) ◽  
pp. 561-568 ◽  
Author(s):  
K. A. Wright ◽  
R. B. Cain
Keyword(s):  
Microbial Metabolism ◽  
Heterocyclic Ring ◽  
Ring Cleavage ◽  
Carboxyl Group ◽  
Metabolic Fate ◽  
Methyl Group ◽  
End Products ◽  
Pyridinium Compounds

Extracts of Achromobacter D formed CO2, methylamine, succinate and formate as metabolic end-products from N-methylisonicotinic acid (4-carboxy-1-methylpyridinium chloride). The origin of the CO2 in the 4-carboxyl group and of the methylamine in the N-methyl group of N-methylisonicotinate was demonstrated with carboxyl-14C- and N-Me-14C-labelled substrates respectively. The carbon skeletons of formate and succinate were shown to arise from the C-2 and the C-3–C-6 atoms of the heterocyclic ring respectively by using N-methyl[2,3-14C2]isonicotinate. This result is consistent with ring cleavage by the organism between C-2 and C-3.

N.M.R. spectra and stereochemistry of the bipyridyls. II. Dimethyl-substituted bridged biquaternary salts of 2,2'-bipyridyl

1967 ◽  
Vol 20 (6) ◽  
pp. 1213 ◽  
Author(s):  
TM Spotswood ◽  
CI Tanzer
Keyword(s):  
Spectral Data ◽  
Qualitative Agreement ◽  
Room Temperature ◽  
Chemical Shifts ◽  
Heterocyclic Ring ◽  
Molecular Models ◽  
Methyl Group ◽  
Electronic Spectral Data ◽  
Factors Influencing ◽  
Good Agreement

The analysis of the N.M.R. spectra of nine dimethyl-substituted bridged biquaternary salts of 2,2?-bipyridyl is reported, and the results are discussed in relation to the several factors influencing the relative chemical shifts of heterocyclic ring protons and methyl group protons. Interplanar angles are calculated for all compounds and are shown to be in good agreement with angles estimated from molecular models and in qualitative agreement with electronic spectral data. Compounds with 3,3?-dimethyl substituents are shown to be in rigid dissymmetrically twisted conformations at room temperature, and evidence is presented that conformational inversion in the bipyridyl series is more difficult than in the corresponding singly bridged biphenyl series. Six of the compounds reported here have not previously been described.

Stereochemistry of bimolecular nucleophilic opening of a dioxolenium ring fused to an anchored cyclohexane system

1969 ◽  
Vol 47 (9) ◽  
pp. 1445-1459 ◽  
Author(s):  
J. F. King ◽  
A. D. Allbutt
Keyword(s):  
Transition States ◽  
Heterocyclic Ring ◽  
The Other ◽  
Cyclohexane Ring ◽  
Methyl Group ◽  
Other Hand ◽  
Opening Ratio ◽  
Nucleophilic Reagents

This paper describes the characterization of certain dioxolenium salts in which the heterocyclic ring is fused (via positions-4 and -5) to an anchored cyclohexane ring, and the steric course of their bimolecular cleavage with nucleophilic reagents. It was found that diaxial opening is normally favored strongly over diequatorial; this is accounted for in terms of differences in angle strain in the transition states. The presence of an axial (angular) methyl group gave a preference for diequatorial opening; on the other hand an analogous investigation of the diaxial: diequatorial opening ratio with epoxides showed the stereochemistry of the reaction to be virtually insensitive to an angular methyl group. These observations are interpreted in terms of the different non-bonded interactions arising from the different geometrical arrangements of epoxides and dioxolenium ions. The variation in the diaxial: diequatorial opening ratio is shown to be of significance in the interpretation of rates of diaxial → diequatorial rearrangement.

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