Infrared, 1 H and 13 C NMR spectral studies of some 4-((1,1'-biphenyl)-4- yl)-6-(substituted phenyl)-5,6-dihydro-4H-1,3-oxazine-2-amines: Assessment of substituent effects

About ten titled compounds were prepared by microwave assisted silica-phosphoric acid catalysed cyclization of substituted styryl 4-biphenyl ketones and urea under solvent-free conditions. The infrared frequencies (ν, cm -1 ) of NH 2, C=N, COC stretches, NMR spectral chemical shifts(δ, ppm) of NH 2, H 4-6, C=N, and C4-6 were assigned and correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the results of statistical analysis, the effect of substituents on the infrared frequencies (ν, cm -1 ) and NMR chemical shifts (δ, ppm) has been studied.