B V S Reddy

Zinc-mediated Barbier reactions of pyrrole and indoles: a new method for the alkylation of pyrrole and indoles

Abstract Pyrrole and indoles react smoothly with alkyl halides such as allyl bromide, prenyl bromide, crotyl bromide and propargyl bromide in the presence of zinc metal in THF to afford the corresponding 3- and 2-alkyl pyrrole and 3-alkyl indole derivatives in good yields with high regioselectivity.

1,4-Conjugate addition of allyltrimethylsilane to α,β-unsaturated ketones

Abstract α,β-Unsaturated ketones smoothly undergo conjugate addition with allyltrimethylsilane in the presence of a catalytic amount of elemental iodine under very mild and convenient conditions to afford the corresponding Michael adducts in high yields with high selectivity.

Indium-mediated facile cleavage of the t-butoxycarbonyl group from di-t-butylimidodicarbonate

Di-t-butylimidodicarbonates are selectively and efficiently deprotected to the corresponding mono-BOC protected amines in high yields using indium or zinc metal in refluxing methanol. Simple BOC and CBz protected amines are unaffected by these conditions.

Stability-Indicating HPLC Method for the Determination of Darunavir Ethanolate

A novel stability-indicating reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the quantitative determination of darunavir ethanolate, an HIV-1 protease inhibitor. The chromatographic separation was achieved using an X-Bridge C18 (150 × 4.6 mm × 3.5 µm) HPLC column in isocratic mode employing 0.01M ammonium formate (pH.3.0) buffer and acetonitrile in the ratio of 55:45 (v/v) with a flow rate of 1.0 mL/min. The detector wavelength was monitored at 265 nm and the column temperature was maintained at 30°C. Darunavir ethanolate was exposed to thermal, photolytic, acid, base and oxidative stress conditions. Considerable degradation of the drug substance was found to occur under acid, base and oxidative stress conditions. The peak homogeneity data of darunavir ethanolate obtained by photodiode array detection demonstrated the specificity of the method in the presence of degradants. The degradation products were well resolved from primary peak of darunavir, indicating that the method is specific and stability-indicating. The HPLC method was validated as per International Conference on Harmonization guidelines with respect to specificity, precision, linearity, accuracy and robustness. Regression analysis showed a correlation coefficient value greater than 0.999. The accuracy of the method was established based on the recovery obtained for darunavir ethanolate.

Montmorillonite Clay‐Catalyzed Three‐Component Coupling Reactions: A Facile Synthesis of Homoallylic Amines

Homoallylic amines are synthesized by the three-component coupling reaction of aldehydes, amines and allyltributylstannane using a heterogeneous solid acid catalyst, montmorillonite KSF, under mild reaction conditions to afford the corresponding homoallylic amines in excellent yields.

Genetic Analysis of Traits Contributing to Stalk Sugar Yield in Sorghum

Sweet sorghum (Sorghum bicolor (L.) Moench) is a potential raw material for production of ethanol that on blending in petrol is expected to meet the energy demand and address the environmental issues. Well-developed hybrid technology will make the crop remunerative to the farmers. Hence, gene action and best combining female and male parents for sugar yield in sweet sorghum (Sorghum bicolor (L.) Moench) and the association of sugar yield with other agronomic traits was studied in 171 hybrids developed by crossing 19 female parents with nine male parents in line × tester design and evaluated during both rainy and postrainy seasons of 2006. The significant differences between the seasons for all the traits suggested that these traits are greatly influenced by the environment. The lines (female parents) ICSA 38, ICSA 479, ICSA 702, ICSA 675 and ICSA 474 and the restorers (male parents), SSV 74 and SSV 84 combined well for sugar yield during rainy season and the lines, ICSA 702, ICSA 38 and ICSA 474 and the restorers, ICSV 93046, SPV 1411 and ICSV 700 combined well during postrainy season. The magnitude of SCA variance was higher suggesting the importance of non-additive gene action in inheritance of all the traits though both additive and dominant genes controlled overall sugar yield during both the seasons. Hence, selection in early generation would be ineffective and recurrent selection with periodic intercrossing is advocated. However, breeding good combining restorer parents can fetch high sugar yield in postrainy season. There is an indication of existence of transgressive segregation for sugar yield that can be exploited. The sugar yield was weak though significantly correlated with high brix and poor grain yield during both the seasons requiring extensive crossing to improve these traits simultaneously. Keeping in view mean performance, SCA effects and heterobeltiosis, the hybrids, ICSA 474 × SSV 84, ICSA 24001 × ICSR 93046 and ICSA 474 × SPV 422 were identified promising for rainy season and the hybrids ICSA 24001 × SPV 1411 and ICSA 511 × ICSV 93046 were identified for postrainy season.

Performance of A1, A2, A3, A4(M), A4(G) and A4(VZM) cytoplasms based iso-nuclear sorghum hybrids for shoot fly resistance across-rainy and post-rainy seasons

Breeding for resistance to sorghum shoot fly in A1 CMS system has been only partially successful. To compare the alternate Cytoplasmic Male Sterility (CMS) systems for shoot fly resistance, 72 hybrids produced by crossing 36 A-lines carrying six diverse cytoplasms namely, A1, A2, A3, A4(M), A4(G), A4(VZM), each in six nuclear backgrounds with two common fertility restorers. The hybrids were evaluated during 2006 and 2007 rainy and post rainy seasons in shoot fly screening trials at ICRISAT. ANOVA indicated absence of overall cytoplasmic influence on dead hearts%. The general (GCA) and specific combining ability (SCA) estimates suggested that inheritance for deadhearts was governed by additive-type of gene action. For GCA effects, the A2 and A4(M) cytoplasms and for SCA effects, the A4(G) and A4(M) cytoplasms were superior over other cytoplasms. Overall, the A4(M) cytoplasm seemed to contribute to shoot fly resistance in hybrid combinations. However, use of all the six alternate cytoplasms should not increase the risk of shoot fly in commercial grain production.