Investigation of intramolecular hydrogen bonding in carbalkoxy derivatives of N15-?-enamino ketones

(Het)aroylpyruvic acids and their derivatives as promising building blocks for organic synthesis

“…The structure of the compounds 48, stabilised by an intramolecular hydrogen bond (IMHB) in the b-amino vinyl ketone fragment, was confirmed by NMR spectroscopy. 117 The APA arylamides 6 behave in a similar way in reactions with aniline, giving rise to arylamides of 4-aryl-4-oxo-2-phenylaminobut-2enoic acids 49 in 60% ± 93% yields. 29,118 2, 47: R 1 = OEt; R 2 = H; 2, 4, 48: R 1 = OH, OMe; R 2 = Ar H ; 6, 49: R 1 = NHAr H ; R 2 = Ph.…”

Synthesis and study of antiinflammatory and analgesic activity of 6-methyl(phenyl)-3-aroylmethylene-piperazin-2-ones

“…XlV The nH NMR spectra meas-xv ured in DMSO-d6 contain singlet XVl signals at 10.01 -11.08 and 8.98 -XVll 9.01 ppm due to amino groups, xvnl The fact that one amino group sig-xIx nals at. a weaker field than the xx other is evidence of the former xxI group being involved in the intra-xxn XXIII molecular hydrogen bonds [8,9]. The signals due to aromatic protons have the form of multiplets observed in the region 7.33- Table 2).…”

“…The IR spectra of the target IV compounds exhibit absorption v bands in the region of 1682-1696 Vl cm-i (amide carbonyl) and 1600-Vli 1620 era-1 (ketone carbonyl in-VIII volved in the intramolecular hy-IX drogen bonds) [7][8][9]. Two other x bands, observed in the regions of Xl 3140-3264 and 3040-3116 cm -I , Xll are assigned to the stretching vi-Xlli brations of amino groups [2,7].…”