1-Acetyl-2-chloro-3-iminoindoline hydrochloride and its N-acetyl derivatives in nucleophilic substitution reactions

It is shown that the chlorine atom in position 2 of 1-acetyl-2-chloro-3-iminoindoline hydrochloride is readily substituted on treatment with secondary amines and thiophenol. The products of nucleophilic reaction are isolated as 2-substituted 3-aminoindoles or 3-acetylaminoindoles, and as 2-substituted 1-acetyl-3-indolinones. The latter are also formed from 1-acetyl-3-indolinone by successive bromination and treatment with secondary amines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 49–54, January, 1992.     

2-Allylaminothiazolin-4-one in acylation reactions

2-Acetylallylamino-4-acetoxythiazole is obtained via treatment of 2-allylaminothiazolin-4-one with acetic anhydride for a short period of time. After extended reaction times with a mixture of acetic anhydride and acetic acid a non-condensed bicyclic derivative of thiazolidin-4-one is obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1135–1140, August, 1987.     

Laser flash photolysis of fluorinated aryl azides in neutral and acidic solutions

Laser flash photolysis of perfluoro-4-biphenyl azide andN-propyl-4-azido-2,3,5,6-tetrafluorobenzylamide in acetonitrile, water-acetonitrile mixtures, and HCl-containing solutions was studied. The absorption spectra of primary intermediates, singlet arylnitrenes(2a(S) and2b(S), respectively), were recorded. The absolute rate constants of their intersystem crossing in MeCN were measured, and the corresponding Arrhenius parameters were found from the temperature dependences of the rate constants of isomerization of singlet arylnitrenes2a(S) and2b(S) to azirines. Protonation of singlet arylnitrenes2a(S) and2b(S) was observed, the rate constants of their protonation were measured, and the transient absorption spectra of arylnitrenium ions were recorded. It was shown by quantum-chemical calculations (the hybrid B3LYP method) that the arylnitrenium ions that formed have the singlet ground state and the singlet-triplet gap is ∼20 kcal mol⁻¹. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 49–54, January, 2000.     

New synthesis of 2-aryl-3-hydroxy(alkoxy)-4-quinolones by ring expansion of 1-acetyl-2-arylmethylene-3-indolinones

Translated from Khimiya Geterotsiklicheskikh Soedinenii,'No. 2, pp. 279–280, February, 1992.     

Laser flash photolysis of fluorinated aryl azides in neutral and acidic solutions

Laser flash photolysis of perfluoro-4-biphenyl azide andN-propyl-4-azido-2,3,5,6-tetrafluorobenzylamide in acetonitrile, water-acetonitrile mixtures, and HCl-containing solutions was studied. The absorption spectra of primary intermediates, singlet arylnitrenes(2a(S) and2b(S), respectively), were recorded. The absolute rate constants of their intersystem crossing in MeCN were measured, and the corresponding Arrhenius parameters were found from the temperature dependences of the rate constants of isomerization of singlet arylnitrenes2a(S) and2b(S) to azirines. Protonation of singlet arylnitrenes2a(S) and2b(S) was observed, the rate constants of their protonation were measured, and the transient absorption spectra of arylnitrenium ions were recorded. It was shown by quantum-chemical calculations (the hybrid B3LYP method) that the arylnitrenium ions that formed have the singlet ground state and the singlet-triplet gap is ∼20 kcal mol⁻¹. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 49–54, January, 2000.     

Pyrido[2,3-d]pyrimidines 4. Synthesis and some transformations of oxo(hydroxy)pyrido[2,3-d]pyrimidines

The cyclization of 5-cyanoacetyl-6-aminouracils in acidic media was accomplished. The structures of the pyrido[2,3-d]pyrimidines obtained and their properties are discussed.See [1] for Communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 674–680, May, 1991.     

A Laser Flash-Photolysis Study of the Bimolecular Reactions of Singlet Fluorinated Arylnitrenes

The kinetics and mechanisms of the reactions of singlet perfluoro-4-biphenylnitrene and N-propyl-4-nitreno-2,3,5,6-tetrafluorobenzylamide with various amines, pyridine, and dimethylsulfoxide were studied by laser flash photolysis. The reactions of singlet arylnitrenes with amines are two-step processes. The primary step of the process is adduct formation; the rate constant of this reaction is high and lies within the range 4 × 10⁷–2 × 10⁸l mol^–1s^–1for the tested secondary amines. The second step (1,2-hydrogen shift) was accelerated in the presence of water.