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37. Pyrano[4,3- d]pyrimidinium salts 4. Transformations of 5,7-diaryl-1,3-dimethyl-2,4-dioxo-1 H,3 H-pyrano[4,3- d]pyrimidinium bromides under the action of phenylhydrazines and aromatic acid hydrazides.

Author

Kostrub, V. V., Tsupak, E. B., and Smol'yakov, A. F.

Subjects
BROMIDES, HYDRAZINES, CHEMICAL reactions, PHENYLHYDRAZINE, SALTS
Abstract

Reactions of 5,7-diaryl-1,3-dimethyl-2,4-dioxo-1 H,3 H-pyrano[4,3- d]pyrimidinium bromides with phenylhydrazines and aromatic acid hydrazides have been studied. The reaction of the salts indicated with phenylhydrazine at ∼20 °C results in the pyrylium ring opening, whereas elevated temperature leads to recyclization products, i.e., 1,3-dimethylpyrido[4,3- d]pyrimidine-2,4(1 H,3 H)-diones. The reactions of the starting bromides with m-carboxyphenylhydrazine and aromatic acid hydrazides lead to 6-(R-amino)-1,3-dimethyl-2,4-dioxo-1 H,3 H-pyrido[4,3- d]-pyrimidinium salts. [ABSTRACT FROM AUTHOR]

Published
2009
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38. Pyrano[4,3- d]pyrimidinium salts 3. Reactions of 1,3-dimethyl-2,4-dioxo-1 H,3 H-pyrano[4,3- d]pyrimidinium salts with azomethines.

Author

Kostrub, V. V. and Tsupak, E. B.

Subjects
SALTS, ALDEHYDES, AROMATIC compounds, CHEMICAL reactions, ORGANIC compounds
Abstract

Reactions of 1,3-dimethyl-2,4-dioxo-1 H,3 H-pyrano[4,3- d]pyrimidinium salts with azomethines have been studied. The reactions lead to 1,3-dimethyl-2,4-dioxo-1 H,3 H-pyrido-[4,3- d]pyrimidinium salts and aromatic aldehydes. [ABSTRACT FROM AUTHOR]

Published
2009
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40. Pyrrolopyrimidines. 2.* Synthesis and oxidative conversions of 5-amino-1,3-Dimethylpyrrolo[3, 2-d]pyrimidine-2, 4-diones

Author

Tkachenko, Yu. N., Tsupak, E. B., and Pozharskii, A. F.

Abstract

By the action of hydroxylamine-O-sulfonic acid in an alkaline medium on 1,3-dimethyl- and 1,3-dimethyl-7-bromopyrrolo[3,2-d]pyrimidine-2,4-diones, their 5-amino derivatives have been obtained. It has been shown that the oxidation of these derivatives leads to the formation of the corresponding tetrazenes and products of deamination, the ratio of which is determined by the type of oxidizing agent and by the reaction conditions. I-Aminoindole behaves analogously.

Published
1995
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