... of a program directed towards the synthesis and the spectral property determination of heterocyclic deriva- tives ... or deuteriu- dimethyl sulfoxide solution containing tetramethylsilane as the internal standard with chemical shifts 5 ... 6.95 (d, 1H, J = 2.4 Hz, 4-H), 7.35 (d, 1H, J = 8.7 Hz ...