856 research outputs found

    Synthesis & anticonvulsant activity of some condensed imidazoles

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    2-Mercapto-4,5-dihydroimidazole (la), 2-mercapto-3,4,5,6-tetrahydropyrimidine (lb) and 2-mer-_capto-3,4,5,6-tetrahydro-7H-l,3-diazepine (1c) react with methyl iodide to give the corresponding mercaptomethyl derivatives (2a-2c). Reaction of these mercaptomethyl compounds with aminoacetaldehyde diethyl acetal followed by treatment with hydrochloric acid affords lH-2,3-dihydroimidazo[l,2-a]imidazole (4), 5,6,7,8-tetrahydroimidazo[l,2-a]pyrimidine (19) and 9H-5,6,7, 8-tetrahydroimidazo[l,2-a]-[l,3]-diazepine (22), respectively. These condensed imidazoles have been reacted with aromatic acid chlorides, isocyanates and isothiocyanates. The structure and anticonvulsant activity of these compounds are described

    Nitroimidazoles: Part XI. Some Halonitro- & dinitroimidazoles

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    Methylation of 2-chloro-4-nitroimidazole (6), obtained from imidazole in four steps, either with dimethyl sulphate or with diazomethane affords a mixture of 2-chloro-l-methyl-5-nitroimidazole (10) and the 4-nitro-isomer (7). The corresponding dinitro compounds 11 and 8 are formed in the methylation of 2,4-dinitroimidazole (5), 8 being converted to 7 by the action of POCl3. Reaction of 10 with the sodium salt of N-methanesulphonyl-2-imidazolidinone provides the potent amoebicide, 1-methylsulphonyl-3-(1-methyl-5-nitroimidazol-2-yl)-2-imidazolidinone (2). The isomer 14 is synthesised from 7 in low yield. Ethylation of 5 leads to preponderant N-alkylation, providing a mixture of l-ethyldinitroimidazoles (9) and (12), but a small amount of N,C-diethyl derivative 15 is also obtained. The formation of 15 from 5 is rationalised. The diiodination product of imidazole is shown to be 4,5-diiodoimidazole (19), nitric acid transforming it to 4-iodo-5-nitroimidazole (20). Methylation of 20 affords a mixture of isomeric 1 -methyliodonitro derivatives (21) and (22). The structures of 21 and 22 are established by 13C NMR data as well as by conversion into morpholine derivatives 26 and 24 respectively which also arise from 1-methylchloronitroimidazoles (25) and (23). A mechanism is proposed for the reported conversion of 5 into 4-chloro-5-nitroimidazole (32) in boiling 2-chloroethanol

    Database on nutritional composition of food fishes from India

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    This database is the first of its kind on fish-food data in the country and is envisaged to serve as a repository of all such nutritional information on different food-fish species. This would also serve as a knowledgebase for different clientele groups, including physicians, nutritionists, planners and consumers to increase the utility of fish as a health food and in clinical nutrition as well. The nutritional information generated could also be helpful in prioritization of fish species for aquaculture depending upon their associated nutritional values

    Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)

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    The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08 ^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical, the second systematic and the third is associated to the ratio of fragmentation fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/- 0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table

    Measurement of the CKM angle γ from a combination of B±→Dh± analyses

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    A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing

    Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−

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    The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions

    Search for CP violation in D+KK+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

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    A model-independent search for direct CP violation in the Cabibbo suppressed decay D+KK+π+D^+ \to K^- K^+\pi^+ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb1^{-1}. The normalized Dalitz plot distributions for D+D^+ and DD^- are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.

    Study of B0(s)→K0Sh+h′− decays with first observation of B0s→K0SK±π∓ and B0s→K0Sπ+π−

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    A search for charmless three-body decays of B 0 and B0s mesons with a K0S meson in the final state is performed using the pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected at a centre-of-mass energy of 7 TeV recorded by the LHCb experiment. Branching fractions of the B0(s)→K0Sh+h′− decay modes (h (′) = π, K), relative to the well measured B0→K0Sπ+π− decay, are obtained. First observation of the decay modes B0s→K0SK±π∓ and B0s→K0Sπ+π− and confirmation of the decay B0→K0SK±π∓ are reported. The following relative branching fraction measurements or limits are obtained B(B0→K0SK±π∓)B(B0→K0Sπ+π−)=0.128±0.017(stat.)±0.009(syst.), B(B0→K0SK+K−)B(B0→K0Sπ+π−)=0.385±0.031(stat.)±0.023(syst.), B(B0s→K0Sπ+π−)B(B0→K0Sπ+π−)=0.29±0.06(stat.)±0.03(syst.)±0.02(fs/fd), B(B0s→K0SK±π∓)B(B0→K0Sπ+π−)=1.48±0.12(stat.)±0.08(syst.)±0.12(fs/fd)B(B0s→K0SK+K−)B(B0→K0Sπ+π−)∈[0.004;0.068]at90%CL
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