Synthesis, Crystal Structures and Antibacterial Activities of Benzohydrazone Derivatives From 4-Diethylaminosalicylaldehyde

Abstract

A series of three new benzohydrazone compounds, C 18 H 21 N 3 O 3 (1), C 19 H 23 N 3 O 3 (2), and C 18 H 20 ClN 3 O 2 (3), derived from the condensation of 4-diethylaminosalicylaldehyde with 2-hydroxybenzohydrazide, 4-methoxybenzohydrazide, and 4-chlorobenzohydrazide, respectively, in methanol, were prepared. The compounds were characterized by elemental analysis, IR spectra, 1 H NMR spectra, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group

A New Fluorescence Turn-On Probe for Aluminum(III) with High Selectivity and Sensitivity, and its Application to Bioimaging

“…Synthesis of ­ N ′‐(4‐diethylamino‐2‐hydroxybenzylidene)‐2‐hydroxybenzohydrazide (1) : A solution of 2‐hydroxybenzohydrazide ( 3 ) (1.52 g, 10 mmol), 4‐(diethylamino)salicylaldehyde ( 2 ) (1.93 g, 10 mmol), and piperidine (0.50 mL) in EtOH (25 mL) was heated at reflux for 4 h. The resulting yellow precipitate was isolated by filtration and then washed with EtOH to give the crude product. Purification by column chromatography (hexane/EtOAc, 2:1→1:1) gave the title compound as a pale yellow solid (2.77 g, 81 % yield): 1 H NMR (500 MHz, [D 6 ]DMSO): δ =8.48 (s, 1 H), 7.87 (d, J =6.5 Hz, 1 H), 7.44–7.42 (m, 1 H), 7.29 (d, J =8.5 Hz, 1 H), 6.97–6.93 (m, 2 H), 6.38 (d, J =8.5 Hz, 1 H), 6.24 (s, 1 H), 3.38 (q, J =7.0 Hz, 4 H), 1.09 ppm (t, J =7.0 Hz, 6 H); 13 C NMR (125 MHz, [D 6 ]DMSO): δ =165.0, 159.8, 159.6, 150.2, 134.5, 132.1, 129.2, 119.5, 117.8, 116.0, 48.5, 11.7 ppm; MS (ESI): m/z =327 [ M ] + .…”

“…Synthesis of N'-(4-diethylamino-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (1): [34] As olution of 2-hydroxybenzohydrazide (3)( 1.52 g, 10 mmol), 4-(diethylamino)salicylaldehyde (2) (1.93 g, 10 mmol), and piperidine (0.50 mL) in EtOH (25 mL) was heated at reflux for 4h.T he resulting yellow precipitate was isolated by filtration and then washed with EtOH to give the crude product. Purification by column chromatography (hexane/EtOAc, 2:1!1:1) gave the title compound as ap ale yellow solid (2.77 g, Fluorometric and UV-vis titrations:S olutions (5.0 mm)o fK + , Co 2 + ,C a 2 + ,B a 2 + ,N i 2 + ,P b 2 + ,H g 2 + ,C e 2 + ,Z n 2 + ,C d 2 + ,F e 3 + ,a nd Al 3 + in CH 3 CN/H 2 O( 1:1 v/v)w ere prepared from the chloride or ni- www.chemistryopen.org trate salt.…”

“…Reagents and conditions:a )Piperidine, EtOH, 81 %. [34] [a] Dr.Y .J iang, L.-L. Sun, G.-Z. Ren are helpful to its further application in areas such as bioimaging.…”

“…To the best of our knowledge, although many Schiff base derivatives bearing a fluorescent moiety have been used to detect various metal ions, Schiff base‐type Al 3+ sensors used for bioimaging remain rare . Here, we report a previously identified Schiff base derivative ( 1 ) (Scheme ) as the fluorescent turn‐on probe for detection of Al 3+ . Compared with the reported probes for Al 3+ , probe 1 can be synthesized easily in high yields.…”

Synthesis, Physicochemical Analyses, and Antibacterial Activity of the Fe(iii) Salt of 4-Amine-N-2-Thiazolyl-Benzene Sulfonamide

“…The activity of complex was better against the S. aureus from the laboratory private patient than against the ATCC 25923 one. Bellú Recently, it has been reported the antibacterial activity of benzohydrazone derivatives against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumonia and the results indicate that the compounds show moderate activities against the growth of the tested strains 33 . …”