61158-02-9Relevant academic research and scientific papers
Synthesis and Rotational Isomerism of 1-Substituted Methyl (S)-[5-(2-Nitrophenyl)-1H-pyrazole-4-carbonyl]alaninates
?enica, Luka,Stopar, Karmen,Friedrich, Miha,Gro?elj, Uro?,Plavec, Janez,Po?kaj, Marta,Podlipnik, ?rtomir,?tefane, Bogdan,Svete, Jurij
, p. 146 - 161 (2016/01/15)
Seven title compounds 12a-g and the (S)-prolinate analogue 13 were prepared in five steps from 2-nitrobenzoic acid (7). Reduction of the nitro group followed by derivatization of the so formed anilines 14 gave the N-alkyl-(15a-c), N-acyl-(16a,b and 19), and N-vinyl derivative 20. NMR spectra of (S)-alanine and (S)-proline derived compounds 12, 13, 14-16, 19, and 20 exhibited two sets of signals corresponding to pairs of conformational diastereomers. The free energy barriers of rotation, ΔG?298 = 82-86 kJ mol-1, were determined by 1H NMR for 12a, 12d, 12f, and 12g and evaluated by DFT calculations.
