Acid deuterium exchange in benzazoles

Journal Article · Fri Oct 31 23:00:00 EST 1986 · Chem. Heterocycl. Compd. (Engl. Transl.); (United States)

DOI:https://doi.org/10.1007/BF00519540· OSTI ID:6423741

Tupitsyn, I F; Zatsepina, N N; Belyashova, A I; Kane, A A

The kinetics of acid deuterium exchange in benzazoles carrying electron-donor substituents in the 5-, 6-, or 7-positions have been studied. Mass spectrometric studies have shown that exchange in 5-methoxy-1,2-dimethylbenzimidazole takes place exclusively at one position in the benzene ring, in 5-chloro-, 7-chloro-, 5-methoxy-2-methylbenzothiazole and 6-methoxy-2-methylbenzoxazole simultaneously in two positions, and in 6-methoxy-2-methylbenzothiazole the hydrogen at all three possible positions is exchangeable. Using quantum chemical reactivity indices (CNDO/2) in dynamic and state approximations, the orientational features of the reaction have been ascertained. The lack of agreement between the reactivities of the most reactive sites to exchange in heteroaromatic bicycles of similar structure and electrophilic localization energies is explained by differences in the energy profile of the reaction.

• Research Organization: State Institute of Applied Chemistry, Leningrad, USSR
• OSTI ID: 6423741
• Journal Information: Chem. Heterocycl. Compd. (Engl. Transl.); (United States), Journal Name: Chem. Heterocycl. Compd. (Engl. Transl.); (United States) Vol. 22:5; ISSN CHCCA
• Country of Publication: United States
• Language: Russian

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
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640302 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ACTIVATION ENERGY
AROMATICS
ATOMIC MODELS
AZOLES
BENZENE
BENZIMIDAZOLES
BENZOTHIAZOLES
BENZOXAZOLES
BINDING ENERGY
CHARGE DISTRIBUTION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPUTERIZED SIMULATION
DEUTERATION
DEUTERIUM
DEUTERIUM COMPOUNDS
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROGEN TRANSFER
IMIDAZOLES
ISOTOPE RATIO
ISOTOPES
ISOTOPIC EXCHANGE
KINETICS
LIGHT NUCLEI
MASS SPECTRA
MATHEMATICAL MODELS
MECHANICS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXAZOLES
QUANTUM MECHANICS
REACTION KINETICS
SIMULATION
SPECTRA
STABLE ISOTOPES
THIAZOLES
VALENCE