Acid-Catalyzed Cleavage of Some Chromone, Coumarin and Pyrone Derivaties of Aminomethylphosphonic Acid. Products and Kinetics of the ReactionB

• Autorzy: Boduszek B. , Latajka R. , Walkowiak U.
• Języki publikacji: EN

Abstrakty

EN

Treatment of chromone-2, coumarin-4 and pyrone-2 derivatives of N-benzylaminomethylphosphonic acid with strong mineral acids leads to formation of the corresponding heterocyclic amines and phosphoric acid. Kinetic studies of this cleavage reaction demonstrate that protonation has a remarkable influence on a cleavage of C-P bonds. In aq. H2SO4, cleavage of the acids 1-3 exhibits a kinetic dependence on [H+]. The measured solvent isotope effect (kH/kD) was about 1.5 for the 1 and 2 and only 1.1 for the 3. The existence of the isotope effect shows that protons are involved on the rate-determining step. The data obtained suggest that the protonated phosphonate molecule is split by a dissociative mechanism with A-SE2 character and this is combined with an elimination of the phosphonate group as a positive-charged phosphorus moiety.

Słowa kluczowe

EN

cleavage; protonation; chromone; coumarin and pyrone derivaties of aminomethylphosonic acid; kinetics; isotope effect; activation parameters

• Wydawca: Polskie Towarzystwo Chemiczne
• Czasopismo: Polish Journal of Chemistry
• Rocznik: 2001
• Tom: Vol. 75, nr 1
• Strony: 63--69
• Opis fizyczny: Bibliogr. 13 poz., rys.

Twórcy

autor

Boduszek B.

• Institute of Organic Chemistry, Biochemistry and Biotechnology, Wroclaw University of Technology, 50-370 Wroclaw, Poland

autor

Latajka R.

• Institute of Organic Chemistry, Biochemistry and Biotechnology, Wroclaw University of Technology, 50-370 Wroclaw, Poland

autor

Walkowiak U.

• Institute of Organic Chemistry, Biochemistry and Biotechnology, Wroclaw University of Technology, 50-370 Wroclaw, Poland

Bibliografia

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