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Start Over Author "Sheng-Zhen Xu" Topic wittig reaction
8 results on '"Sheng-Zhen Xu"'

5. New Efficient Synthesis of 2-Substituted Benzothieno[3,2-d]pyrimidin-4(3H)-ones via a Tandem Aza-Wittig Reaction

Author

Ming-Wu Ding, Yang-Gen Hu, and Sheng-Zhen Xu

Subjects
Sodium ethoxide, Chemistry, Aryl, Sodium, Organic Chemistry, chemistry.chemical_element, General Medicine, Medicinal chemistry, Catalysis, Potassium carbonate, chemistry.chemical_compound, Wittig reaction, Alkoxide, Structural isomer, Organic chemistry, Carbodiimide
Abstract

1-Aryl-3-[2-(ethoxycarbonyl)benzothien-3-yl]carbodiimides 4, obtained from aza-Wittig reactions of iminophosphorane 3 with aryl isocyanates, reacted with secondary amines, phenols, or alkanols in the presence of a catalytic amount of potassium carbonate or sodium alkoxide to give 2-substituted benzothieno[3,2-d]pyrimidin-4(3H)-ones 6 in good yields. The reaction of carbodiimides 4 with primary amines RNH 2 (R ≠ H, Me) in the presence of sodium ethoxide selectively produced one regioisomer 8 via a base-catalyzed cyclization mechanism. However, a different regioisomer 9 was obtained when primary amines RNH 2 (R = H, Me) were used in the absence of sodium ethoxide via a direct cyclization mechanism.

Published
2007

6. Efficient synthesis of benzothieno[3,2- d]-imidazo[1,2- a]pyrimidine-2,5-(1 H, 3 H)-diones via a tandem aza-wittig/heterocumulene-mediated annulation.

Author

Sheng-Zhen Xu, Jing Wu, Min-Hui Cao, and Ming-Wu Ding

Subjects
*WITTIG reaction, *ISOCYANATES, *FIBRINOLYTIC agents, *CARDIOTONIC agents, *X-ray diffraction, *MELTING points
Abstract

Carbodiimide 2, obtained from aza-Wittig reaction of iminophosphorane 1 with aromaic isocyanate, reacted with α-amino ester in the presence of catalytic amount of sodium ethoxide to give selectively new tetracyclic benzothieno[3,2-d]-imidazo[1,2-a]pyrimidine-2,5-(1H, 3H)-diones 5 in good yields. XRay structure analysis of 5b verified the proposed structure and the reaction selectivity. [ABSTRACT FROM AUTHOR]

Published
2010
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7. 2-Morpholino-3- p-tolyl­benzo[4,5]thieno[3,2- d]pyrimidin-4(3 H)-one.

Author

Sheng-Zhen Xu, Yang-Gen Hu, Ming-Guo Liu, and Ming-Wu Ding

Subjects
*HYDROGEN bonding, *WITTIG reaction, *HYDROGEN, *HETEROCYCLIC chemistry, *MOLECULAR association, *CARBOXYLIC acids
Abstract

In the crystal structure of the title compound, C21H19N3O2S, there are two crystallographically independent mol­ecules, which are linked by C—H⋯O hydrogen bonds and π–π inter­actions. [ABSTRACT FROM AUTHOR]

Published
2006
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8. 2-Diethylamino-3-(3-methylphenyl)-1-benzo-furo[3,2-d]pyrimidin-4(3H)-one.

Author

Ming-Guo Liu, Ju-Zhen Yuan, Yang-Gen Hu, and Sheng-Zhen Xu

Subjects
*PYRIMIDINES, *HETEROCYCLIC compounds, *WITTIG reaction, *BIOACTIVE compounds, *CHEMICAL structure, *ORGANIC compounds
Abstract

The article presents information on the organic compound 2-Diethylamino-3-(3-methylphenyl)-1-benzo-furo[3,2-d] pyrimidin-4(3H)-one. Benzofuropyrimidines derivatives of are of great importance because of their remarkable biological properties. Recently the derivatives of heterocycles are prepared through an aza-Wittig reaction. The heterocyclic compound, 2-Diethylamino-3-(3-methylphenyl)-1-benzo-furo[3,2-d] pyrimidin-4(3H)-one may be used as a new precursor for obtaining bioactive molecules. Its structure is presented here.

Published
2006
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