Synthesis, characterization and density functional theory investigations of monoacyl aniline derivatives

Abstract

ABSTRACT. We synthesized a number of aniline derivatives containing acyl groups to compare their barriers of rotation around the N-CO groups. Geometry optimization for all the rotamers have been performed using density functional theory (DFT) at the B3LYP/6-31G** level of theory. For each stationary point we carried out vibrational frequency calculations at the same level to characterize their nature as minima or transition states. The methoxy group substituent on the benzene ring causes some changes in the C-C bond distances. We carried out potential energy surface scanning to find out all possible low-energy conformations, which would be used as the initial structure for further molecular calculations. There were only three kinds of conformations with local minimum potential energy and two transition states. The optimized bond lengths and bond angles are in better agreement with the experimental values.

Variable temperature 1H and 13C NMR study of restricted rotation in N,N-bis(2-hydroxyethyl)acetamide

“…However these were all in the range 3.4-3.8, which is at odds with both the previous spectra reported in CDCl3 [4,7]. By moving to CD3SOCD3 separate clearly defined triplets were observed in the range 3.3- When 13 C NMR spectra were run in both solvents, the expected pattern was observed with a single carbonyl signal, two widely separated signals for CH2N and two slightly non-equivalent signals for CH2O ( Table 2).…”

“…The spectra obtained in CDCl3 are not in agreement with the data recently published by two separate groups [4,7], which appear to be erroneous. Quantification of the barrier to rotation by means of a variable temperature study in CD3SOCD3 gives values well within the normal range for such amides.…”

“…By moving to CD3SOCD3 separate clearly defined triplets were observed in the range 3.3- When 13 C NMR spectra were run in both solvents, the expected pattern was observed with a single carbonyl signal, two widely separated signals for CH2N and two slightly non-equivalent signals for CH2O ( Table 2). The clearly defined patterns obtained (Figure 2) give no hint as to origin of the erroneous literature data [4]. Having established the expected pattern of nonequivalence of the two hydroxyethyl groups at RT due to restricted rotation of the acetyl group, CD3SOCD3 was chosen as the preferred solvent for a variable temperature study and spectra were obtained for both 1 H and 13 C over the range 25-100 C.…”

“…It has also been mentioned both as a product and a reference compound in a series of recent studies on selective acyl transfer reactions in which acetylating agents such as N-acetyl-4,6-dimethylpyrimidine-2-thione [3] and 3-(N,Ndiacetylamino)quinazolin-4-ones [4] were reacted with various amines including diethanolamine.…”

Antibacterial activities, DFT and QSAR studies of quinazolinone compounds

“…Recently, we have optimized the geometries of organic compounds different compounds by using B3LYP functional and proved that it is reliable approach to reproduce the experimental data [8,[14][15][16][17][18][19]. The absorption wavelengths have been computed by using TD-DFT [20,21].…”