Variations in product in reactions of naphthoquinone with primary amines (original) (raw)
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Synthesis of 1,4-naphthoquinones derivatives under non-conventional conditions and in silico studies
Proceedings of 6th International Electronic Conference on Medicinal Chemistry, 2020
Microwave irradiation synthesis were completed within ≤ 10 min, whereas similar reactions under conventional heating at reflux gave lower or similar yields, with comparatively longer reaction times. For arylamines derivatives (4a-d and 5a-d) yields were significantly higher for 1,4-NQ derivatives (4a-d), due to the presence of CaCO 3. For alkylamines derivatives (4e-g and 5e-g) similar results were obtained with both precursors. Compounds were obtained by one-step Michael addition to C2 of nuclear naphthoquinone structure. Structural characterization were assigned based on their 1 H and 13 C NMR spectra and two-dimensional NMR (HSQC and HMBC) techniques. ESI-Mass spectrometry was used to corroborate NMR data and all compounds exhibited the expected m/z signals correspondent to the protonated molecules [M+H] + .
Novel 2-Amino-3-(2,4-dinitrophenylamino) Derivatives of 1,4-Naphthoquinone
ChemInform, 2005
The strong electron withdrawing nature of a 2,4-dinitrophenylamino group when attached to a chloro-naphthoquinone enhances the displacement of the chlorine atom by various aliphatic, cyclic and aromatic amines. A new series of 2-amino-3-(2,4dinitrophenylamino) derivatives of 1,4-naphthoquinone were prepared. Three absorption maxima in the UV-vis spectra were typical, including one at 430-550 nm assigned to a CT transition.
Zeitschrift für Kristallographie - Crystalline Materials, 2018
X-ray crystallography reveals the common feature of the title compounds is a 1,4-naphthoquinone ring system with a substituted phenoxy residue adjacent to an oxo-group to give 1 (H), 2 (3-Br), 3 (3-CF3), 4 (4-CN) and 5 (4-NO2). To a first approximation the fused ring system along with the two oxo substituents is planar with the major difference between the molecules relating to the relative orientations of the pendant phenoxy residues: dihedral angles range from 56.56(4)° (3) to 87.52(10)° (2). The presence of intermolecular C–H···O interactions is the common feature of the supramolecular association in the crystals of 1–5. In each of 1 and 5, these extend in three-dimensions but, only to supramolecular dimers in 4, chains in 2 and layers in 3. Each crystal also features C=O···π interactions, pointing to the importance of these points of contact in this series di-oxocompounds. In 2, these, along with C–Br···π interactions lead to a three-dimensional architecture. For 3, the C=O···π ...
Reactions of 2- Amino-1,4- Naphthoquinone with Aldehydes
2003
Reactions of 2-amino-1,4-naphthoquinone with aldehydes give 2-(N-alkenyl)amino- 1,4-naphthoquinones (7) under neutral conditions while they give substituted 1H-2,4-dihydronaphtho(2,3-d)1,3-oxazine-5,10-diones (8) using catalytic amount of trifluoroacetic acid.
Conformational analysis of chloroalkyl derivatives of 1,4-naphthoquinone
Journal of Molecular Structure, 2000
Studies of Kerr effect and 1 H and 13 C NMR spectra of 2-substituted 3-g-chloropropyl-and 3-b-chloroethyl-1,4-naphthoquinones are reported. The analysis of the experimental data indicates that the studied compounds exist in solution predominantly in the anti-peri-planar (ap) form. Formation of cyclic structures stabilized by local intermolecular interactions was not observed.
Novel N,S-Substituted naphthoquinone analogues from aminonaphthoquinones
The European Chemistry and Biotechnology Journal, 2024
In this study, novel N,S-substituted naphthaquinone analogues (2, 4, 6, and 8) were synthesized from the reactions of previously known aminonaphthaquinone derivatives (1, 3, 5, and 7) with allyl mercaptan. 2-(allylthio)-3-(4-phenylpiperazin-1-yl)naphthalene-1,4-dione (2), 2-(allylthio)-3-(4-(2fluorophenyl)piperazin-1-yl)naphthalene-1,4-dione (4), 2-(allylthio)-3-(4-benzylpiperidin-1yl)naphthalene-1,4-dione (6) and 2-(4-chlorophenylamino)-3-(allylthio)naphthalene-1,4-dione (8) were obtained from the reactions of 2-chloro-3-(4-phenylpiperazin-1-yl)naphthalene-1,4-dione (1), 2-chloro-3-(4-(2-fluorophenyl)piperazin-1-yl)naphthalene-1,4-dione (3), 2-(4-benzylpiperidin-1-yl)-3chloronaphthalene-1,4-dione (5), and 2-(4-chlorophenylamino)-3-chloronaphthalene-1,4-dione (7) with allyl mercaptan according to the general synthesis procedure. Synthesized new naphthaquinone analogues (2, 4, 6, and 8) were purified by column chromatography. The chemical structures of these novel N,S-substituted naphthaquinone analogues were characterized by spectroscopic methods (FT-IR, NMR, and MS).
Synthesis and characteristics of amino acid derivatives of 1,4-naphthoquinone
Synthesis optimization of a series of 2-amino acid-3-chloro-1,4-naphthoquinones demonstrated feasibility to conduct reactions in mild conditions providing relatively high yields, simple procedure and low time costs. Compounds were characterized with standard methods of chemical analysis and spectroscopic techniques. Physicochemical parameters of weight loss and start melting point were determined. Preliminary screening of synthesized compounds carried out with online based algorithm of prediction of activity spectra for synthesized substances (PASS).
Synthesis and Structural Analysis of Some New Sulfanyl Amino 1,4-Naphthoquinone Derivatives
Journal of the Turkish Chemical Society, Section A: Chemistry, 2017
In this study, some new sulfanyl-substituted amino 1,4-naphthoquinone derivatives which possess two electron-donating groups in the amino fragment were synthesized and their structures were analyzed by spectroscopic techniques. First, 2-chloro-3-[(2,4dimethoxyphenyl)amino]naphthalene-1,4-dione (3a) and 2-chloro-3-[(3,5dimethoxyphenyl)amino]naphthalene-1,4-dione (3b) were obtained from the reactions of dichloro-1,4-naphthoquinone (1) with 2,4-dimethoxyaniline and 3,5-dimethoxyaniline. In the following step, the compounds 3a,b were reacted with aliphatic nucleophiles; ethyl-, 1-propyl-, and 1-pentyl mercaptan. S-nucleophiles attacked the carbon atom of 1,4-naphthoquinone core and displaced the chlorine atom to create target molecules; 2-arylamino-3-(ethylthio)naphthalene-1,4-dione (5a,b), 2-arylamino-3-(propylthio)naphthalene-1,4-dione (5c,d), 2-arylamino-3-(pentylthio)naphthalene-1,4-dione (5e,f) derivatives. The structures of the synthesized compounds were elucidated by utilizing 1D and 2D NMR techniques with additional spectroscopic data (mass and FTIR).
Synthesis and biological evaluation of new amino derivatives of 1,4-naphthoquinone
Synthesized ranks of new biologically active compounds by nucleophilic substitution of chlorine atom in the amino acid chloride derivatives of 1,4-naphthoquinone. All structures characterized with standard methods of chemical analysis and spectroscopic techniques. Experimental biological screening of synthesized compounds carried out. Among the newly synthesized compounds detected non-embryotoxic fungicides and bactericides, which does not cause oxidative stress.