Reactivity of Hydrazine, Some Hydrazine derivatives and Diamines toward Ethyl 2,2-Dicyano-1-aryl (or alkyl)vinylcarbamate

A series of pyrimidinone and dipyrimidinone derivatives 2a-c, 4a-e and 6a-f has been synthesized via the reaction between ethyl 2,2-dicyano-1-aryl(or alkyl)vinylcarbamate derivatives 1a-d and hydrazine derivatives or  diamines. The reactivity of compounds 1a-d toward hydrazine is studied. The result is the formation of triazolones 5a-d rather than pyrimidinone derivatives

Synthesis and Antitubercular Evaluation of Some Novel 1,2,3,6-tetrahydropyrimidine-5-carbonitrile

         In an attempt to find a new class of antitubercular agents, a series of 1,2,3,6-tetrahydropyrimidine-5-carbonitrile were prepared via the reaction  of ethyl N-ethoxycarbonylbenzimidate 2a-b with cyanoacetanilide derivatives 1a-c. These compounds were screened for their antitubercular activity against M. tuberculosis. Several analogues, such as 2,6-dioxo-1-phenyl-4-p-tolyl-1,2,3,6-tetrahydropyrimidine-5-carbonitrile 3a, 1-benzyl-2, 6-dioxo-4-p-tolyl-1,2,3,6-tetrahydropyrimidine-5-carbonitrile 3c and 1-benzyl-2, 6-dioxo-4-phenyl-1,2,3,6-tetrahydropyrimidine-5-carbonitrile 3d exhibited a potent antitubercular activity with an MIC values ranging from 10-35 µg/ml. Structures of the newly synthesized compounds were established by spectral data and HRMS

Ultra Wide Band Audio Visual PHY IEEE 802.15.3c for WMSNs

International audienceIn order to retrieve multimedia content like video and audio at indoor environments, wireless multimedia sensor networks have recently emerged as a good solution. Moreover, Ultra Wide Band technology (UWB) can provide high data rates to transfer the multimedia content in a point-to-point mode. In this paper, we explain the features of UWB technology and investigate the performance of the IEEE 802.15.3c standard in terms of Bit Error Rate (BER) against Signal to Noise Ratio (SNR). The Audio Visual Physical (AV PHY) mode has been implemented and simulated and our results show that encoded AV PHY outperforms the uncoded AV PHY for high and low Convolutional encoder rates. Finally, we emphasized the quality improvements with different UWB standard parameters (coding and modulation) in the context of JPEG image compression

GOP encoding structure in H264/AVC for video transmission over Ultra Wide Band IEEE 802.15.3c

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Adaptive UWB AV PHY IEEE 802.15.3c for compressed SPIHT image transmission

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H.264/AVC Video Transmission over UWB AV PHY IEEE 802.15.3c using UEP and Adaptive Modulation Techniques

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Ultra Wide Band Audio Visual PHY IEEE 802.15.3c for SPIHT-compressed Image Transmission

International audienceRecently, multimedia content delivery applications over wireless environments have been increasingly popular. However, in such applications, the quality may suffer from the distorted wireless environment and the sensitivity of the compressed-stream to transmission errors. In this paper, we propose a solution where the Ultra Wide Band technology (UWB) is used to provide high data rates to transfer a SPIHT compressed image. First, we describe the communication model for the UWB Audio Visual (AV) PHY IEEE 802.15.3c technology and investigate the corresponding performance in terms of Bit Error Rate (BER) against Signal to Noise Ratio (SNR). Then, we emphasize the impact of the UWB chain on the SPIHT compressed image quality with an equal error protection (EEP) scheme.Finally, we provided the unequal error protection (UEP) setup offered by the specified UWB technology to enhance the SPIHT compressed image transmission quality. Simulation results are given in terms of peak signal-to-noise ratio (PSNR) and visual image quality. We show that UEP scheme improves the results in terms of image quality and induces important PSNR gains compared to EEP

Synthesis of 6-Amino-5-cyano-1,4-disubstituted-2(1H)-Pyrimidinones via Copper-(I)-catalyzed Alkyne-azide ‘Click Chemistry’ and Their Reactivity

In this paper we present the room temperature synthesis of a novel serie of 1,4-disubstituted-1,2,3-triazoles 4a-l by employing the (3 + 2) cycloaddition reaction of pyrimidinones containing alkyne functions with different model azides in the presence of copper sulphate and sodium ascorbate. To obtain the final triazoles, we also synthesized the major precursors 6-amino-5-cyano-1,4-disubstituted-2(1H)-pyrimidinones 3a-r from ethyl 2,2-dicyanovinylcarbamate derivatives 2a-c and various primary aromatic amines containing an alkyne group. The triazoles were prepared in good to very good yields

CLICK CHEMISTRY AS AN EFFICIENT TOOL TO ACCESS 6-AMINO-5-CYANO-2(1H)-PYRIMIDINONE DIMERS

Abstract We describe here the synthesis of triazole-linked 6-amino-5-cyano-2(1H)-pyrimidinone dimers using 1,3-dipolar cycloaddition. The azido-precursor was prepared through the reaction of ethyl 2,2-dicyanovinylcarbamate derivatives with p-azidoaniline. The second precursor, a 6-amino-5-cyano-1-(3 or 4-ethynylphenyl)-4-substituted-2(1H)-pyrimidinone, was obtained from ethyl 2,2-dicyanovinylcarbamate derivatives reacting with 3-ethynylaniline or 4-ethynylaniline. Consequently, the two 'click systems' were mixed together in order to obtain the desired dimer