Authors:Vinay Bhaya, Ramesh Joshi and Amol Kulkarni
The continuous-flow Meerwein arylation is demonstrated for a set of few aryl donors (anilines and m-aminoacetophenone) and specific radical acceptors. Homogeneous catalyst (CuBr in HBr and CuCl in HCl) was used to facilitate the reaction. The effect of parameters, viz., temperature, catalyst concentration, residence time, and concentration of the radical acceptor on the yield of the arylated product, was studied. The yield of the aryl derivative obtained by continuous-flow syntheses was always better than the respective experiments in batch mode. Flow synthesis allows easy variation in these parameters and thus allows going close to the maximum possible yields in a system where the relative rates of different reactions create a complex situation. Temperature plays a crucial role by affecting the rates as well as by governing the system homogeneity. The nitrogen bubbles generated in the reaction helped to avoid any channel blockage.
Authors:B. BashyaL, Ramesh Chand, L. Prasad and A. Joshi
Eighty barley genotypes were evaluated for partial resistance components of spot blotch disease of barley caused by Bipolaris sorokiniana under field conditions. Barley genotypes were inoculated with 29 B isolate of Bipolaris sorokiniana and the Area Under Disease Progress Curve (AUDPC), size of lesion, number of lesions leaf−1 and number of spores lesion−1 were recorded for penultimate leaves. A wide range of variation was observed for the components of partial resistance in barley genotypes. AUDPC and size of lesion identified as first principal components for the resistance. Further cluster analysis clustered genotypes into 10 groups and barley genotypes BCU5592, BCU5613, BCU1452, BCU138 and BCU133 exhibited low AUDPC, smaller lesion size, less number of lesions leaf−1 and less number of spores lesion−1. Selecting these genotypes exhibiting resistant components could be helpful in reducing losses caused by disease and thus contribute to increased yield.