1H and 13C chemical shifts for acridines: Part XVII. (1,3‐Benzothiazol‐2‐yl)amino‐9(10H)‐acridinone derivatives

The ¹H and ¹³C NMR resonances for 16 acridin‐9(10H)‐ones substituted with amino or (1,3‐benzothiazol‐2‐yl)amino groups were completely and unequivocally assigned by the concerted application of gs‐COSY, gs‐HMQC and gs‐HMBC experiments. Evidence for hydrogen bond and amino–imino tautomerism is presented for 1‐ and 4‐substituted acridin‐9(10H)‐ones. Copyright © 2002 John Wiley & Sons, Ltd.     

1H and 13C chemical shifts for acridines: Part XVIII. 9‐Chloroacridine and 9‐(N‐allyl)‐ and 9‐(N‐propargyl)acridinamine derivatives

The¹H and ¹³C NMR resonances for acridine derivatives 9‐substituted with chloro, allylamino and propargylamino groups were completely assigned using a concerted application of gs‐COSY, gs‐HMQC and gs‐HMBC experiments. 9‐(N‐Allyl)‐ and 9‐(N‐propargyl)acridinamine derivatives present amino–imino tautomerism including a large broadening of ¹H and ¹³C NMR signals at room temperature. To obtain suitable resolution, therefore, these latter compounds were studied at 370 K in DMSO‐d6 solutions and showed a complete shift towards the imino tautomers. Copyright © 2003 John Wiley & Sons, Ltd.     

NMR and conformational studies of new 5‐phenylpyrrole‐carboxamide derivatives

The ¹H and ¹³C NMR resonances of 22 5‐(5‐substituted‐2‐nitrophenyl)‐1H‐pyrrole‐2‐carboxamides, 22 5‐(5‐substituted‐2‐aminophenyl)‐1H‐pyrrole‐2‐carboxamides, and 9 5‐phenyl‐1H‐pyrrole‐2‐carboxamides were assigned completely using the concerted application of one‐ and two‐dimensional experiments (DEPT, gs‐HMQC and gs‐HMBC). NOE studies and conformational analysis confirm the preferred conformations of such compounds. Copyright © 2009 John Wiley & Sons, Ltd.     

1H, 13C and 15N NMR assignments for N‐ and O‐acylethanolamines,important family of naturally occurring bioactive lipid mediators

The complete ¹H, ¹³C and ¹⁵N NMR signal assignments of some N‐ and O‐acylethanolamines, important family of naturally occurring bioactive lipid mediators, were achieved using one‐dimensional and two‐dimensional experiments (gs‐HMQC and gs‐HMBC). Copyright © 2012 John Wiley & Sons, Ltd.     

NMR spectroscopic characterization of new 2,3‐dihydro‐1,3,4‐thiadiazole derivatives

The ¹H and ¹³C NMR resonances of twenty‐seven 2,2‐dimethyl‐5‐(2‐nitrophenyl‐5‐substituted)‐2,3‐dihydro‐1,3,4‐thiadiazoles, and twenty‐seven 3‐acyl‐5‐(2‐amino‐5‐substituted)‐2,2‐dimethyl‐2,3‐dihydro‐1,3,4‐thiadiazoles were assigned completely using the concerted application of one‐dimensional and two‐dimensional experiments (DEPT, HMQC and HMBC). NOESY experiments, X‐ray crystallography and conformational analysis confirm the preferred conformation of these compounds. Copyright © 2012 John Wiley & Sons, Ltd.     

Investigation of Some Functionalization Reactions of 4‐Benzoyl‐5‐phenyl‐1‐(4‐methoxyphenyl)‐1H‐pyrazole‐3‐carbonyl Chloride and Their Antimicrobial Activity

The 1H‐pyrazole‐3‐carboxylic acid 1 was converted via reactions of its acid chloride 3 with various asymmetrical disubstituted urea and alcohol derivatives into the corresponding novel 4‐benzoyl‐N‐(N′,N′‐dialkylcarbamyl)‐1‐(4‐methoxyphenyl)‐5‐phenyl‐1H‐pyrazole‐3‐carboxamide 4a , b and alkyl 4‐benzoyl‐1‐(4‐methoxyphenyl)‐5‐phenyl‐1H‐pyrazole‐3‐carboxylate 7a‐c , respectively, in good yields (57%‐78%). Friedel‐Crafts reactions of 3 with aromatic compouns for 15 min.‐2 h led to the formation of the 4‐3‐diaroyl‐1‐(4‐hydroxyphenyl)‐5‐phenyl‐1H‐pyrazoles 9a‐c , 4‐benzoyl‐1‐(4‐methoxyphenyl)‐3‐aroyl‐5‐phenyl‐1H‐pyrazoles 10a , b and than from the acylation reactions of 9a‐c were obtained the 3,4‐diaroyl‐1‐(4‐acyloxyphenyl)‐5‐phenyl‐1H‐pyrazoles 13a‐d . The structures of all new synthesized compounds were established by NMR experiments such as ¹H, and ¹³C, as well as 2D COSY and IR spectroscopic data, and elemental analyses. All the compounds were evaluated for their antimicrobial activities (agar diffusion method) against eight bacteria and two yeasts.     

1H, 13C and 31P NMR spectral analysis of monoalkyl (α‐anilinobenzyl)phosphonates and their dipalladium(II) metallocyclic complexes

A ¹H, ¹³C and ³¹P NMR study of monoethyl (HL1) and monobutyl (HL2) esters of (α‐anilinobenzyl)phosphonic acid and their metallocyclic dipalladium complexes (Pd₂L₄,L = L1, L2) in DMSO‐d₆ was performed, based on 1D and 2D homo‐ and heteronuclear experiments including ¹H,¹³C,³¹P,APT,¹H–¹H COSY, ¹H–¹³C COSY, gs‐HMQC and gs‐HMBC NMR techniques. The results obtained are discussed with respect to those for some palladium(II) complexes reported for various anilinobenzylphosphonate derivatives. Copyright © 2002 John Wiley & Sons, Ltd.     

Complete assignment of NMR data of 22 phenyl‐1H‐pyrazoles' derivatives

Complete assignment of ¹H and ¹³C NMR chemical shifts and J(¹H/¹H and ¹H/¹⁹F) coupling constants for 22 1‐phenyl‐1H‐pyrazoles' derivates were performed using the concerted application of ¹H 1D and ¹H, ¹³C 2D gs‐HSQC and gs‐HMBC experiments. All 1‐phenyl‐1H‐pyrazoles' derivatives were synthesized as described by Finar and co‐workers. The formylated 1‐phenyl‐1H‐pyrazoles' derivatives were performed under Duff's conditions. Copyright © 2011 John Wiley & Sons, Ltd.     

Isolation and spectral study of 4‐methyl‐6,8‐dihydroxy‐7H‐benz[de]anthracen‐7‐one

4‐Methyl‐6,8‐dihydroxy‐7H‐benz[de]anthracen‐7‐one was isolated from the sap of Aloe by column chromatography. Its ¹H and ¹³C NMR spectra were completely assigned by utilizing two‐dimensional ¹H‐detected heteronuclear one‐bond (HMQC) and multiple‐bond (HMBC) chemical shift correlation experiments together with ¹H–¹H COSY and DEPT techniques. These techniques were also valuable in assigning the protons and carbons of those benzanthrone compounds which were previously incompletely reported because of the overlap of proton signals. The molecular structure was elucidated by 2D NMR analysis. The spectral properties (MS, IR and UV) are also presented. Copyright © 2003 John Wiley & Sons, Ltd.     

1H, 13C and 15N NMR assignments for N6‐isopentenyladenosine/inosine analogues

The complete ¹H, ¹³C and ¹⁵N NMR signals assignments of some new isopentenyladenosine analogues were achieved using one‐ and two‐dimensional experiments (gs‐NOESY, gs‐HMQC and gs‐HMBC). Copyright © 2010 John Wiley & Sons, Ltd.     

Design,Synthesis, Antifungal Activities and SARs of (R)‐2‐Aryl‐4,5‐dihydrothiazole‐4‐carboxylic Acid Derivatives

Based on the structure of natural product 2‐aryl‐4,5‐dihydrothiazole‐4‐carboxylic acid, a series of novel (R)‐2‐aryl‐4,5‐dihydrothiazole‐4‐carboxylic acid derivatives were designed and synthesized. Their structures were characterized by ¹H NMR, ¹³C NMR and HRMS. The single crystal structure of compound 9b was determined by X‐ray diffraction analysis. The antifungal activities were evaluated for the first time. The bioassay results indicated that most compounds exhibited moderate to good antifungal activities. The antifungal activities of compound 13a (against Cercospora arachidicola Hori), 13d (against Alternaria solani), and 16e (against Cercospora arachidicola Hori) were 61.9%, 67.3% and 61.9%, respectively, which are higher than those of the commercial fungicides chlorothalonil and carbendazim. Moreover, compound 13d exhibited excellent antifungal activities against 7 kinds of the fungi tested (66.7%, 77.3%, 63.0%, 87.9%, 70.0%, 70.0% and 80.0% at 50 µg?mL). Therefore, 13d can be used as a new lead structure for the development of antifungal agents.     

One‐step synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate and its characterization with 1D and 2D NMR techniques

A one‐step method was reported for the synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate by treating 7‐acetamido‐4‐hydroxy‐2‐naphthalenesulfonyl chloride with equal moles of N, N‐dimethylethylenediamine in acetonitrile in the presence of K₂CO₃. The chemical structure of the obtained compounds was characterized by MS, FTIR, ¹H NMR, ¹³C NMR, gCOSY, TOCSY, gHSQC, and gHMBC. The chemical shift differences of ¹H and ¹³C being δ 0.04 and 0.2, respectively, were unambiguously differentiated. Copyright © 2013 John Wiley & Sons, Ltd.     

Characterization of 2‐aryl‐1,3,4‐oxadiazoles by 15N and 13C NMR spectroscopy

¹⁵N NMR chemical shifts of 2‐aryl‐1,3,4‐oxadiazoles were assigned on the basis of the ¹H–¹⁵N HMBC experiment. Chemical shifts of the nitrogen and carbon atoms in the oxadiazole ring correlate with the Hammett σ‐constants of substituents in the aryl ring (r² ≥ 0.966 for N atoms). ¹⁵N NMR data are a suitable and sensitive means for characterizing long‐range electronic substituent effects. Additionally, ¹³C NMR data for these compounds are presented. Copyright © 2003 John Wiley & Sons, Ltd.     

Structural determination of aspericins A?C,new furan and pyran derivates from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61, by 1D and 2D NMR spectroscopy

Three new furan and pyran derivatives named aspericins A? C (1–3), as well as a known asperic acid (4), have been isolated from the marine‐derived fungus Rhizopus sp. 2‐PDA‐61. The complete ¹H and ¹³C NMR assignments for the new compounds were carried out using ¹H, ¹³C, DEPT, COSY, HMQC, HMBC, and NOESY NMR experiments. Compounds 1–3 were evaluated for their cytotoxic activities on P388, A549, HL‐60, and BEL‐7420 cell lines by the MTT and SRB methods. Copyright © 2009 John Wiley & Sons, Ltd.     

Characterization of 4,5‐Dihydro‐1H‐Pyrazole Derivatives by 13C NMR Spectroscopy

The ¹³ C NMR resonances of 19 1‐acyl‐3‐(2‐nitro‐5‐substitutedphenyl)‐4,5‐dihydro‐1H‐pyrazoles, and 19 1‐acyl‐3‐(2‐amino‐5‐substituted)‐4,5‐dihydro‐1H‐pyrazoles, were completely assigned using the concerted application of one‐ and two‐dimensional NMR experiments (DEPT, gs‐HSQC and gs‐HMBC). Copyright © 2012 John Wiley & Sons, Ltd.     

NMR studies on 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐4‐phenyl]‐(2H)phthalazin‐1‐one

An unsymmetrical heterocyclic diamine, 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐4‐phenyl]‐(2H)phthalazin‐1‐one, was synthesized. Its ¹H and ¹³C NMR spectra were completely assigned by utilizing the two‐dimensional heteronuclear ¹³C–¹H multiple‐bond coherence (HMBC) spectroscopy, and heteronuclear ¹³C–¹H one‐bond correlation spectroscopy, homonuclear shift correlation spectroscopy (H,H‐COSY) and rotating frame Overhauser enhancement spectroscopy (ROESY). The structure of the compound was shown to be the phthalazinone rather than the phthalazine ether from cross peaks and chemical shifts of the protons. Copyright © 2002 John Wiley & Sons, Ltd.     

1H‐, 13C‐, and 15N‐NMR chemical shifts for selected glucosides and ribosides of aromatic cytokinins

The ¹H and ¹³C NMR resonances of 16 purine glucosides were assigned by a combination of one‐ and two‐dimensional NMR experiments, including gs‐COSY, gs‐HSQC, and gs‐HMBC, in order to characterize the effect of substituent and the position of glucose unit on the NMR chemical shifts. In addition, ¹⁵N NMR chemical shifts for selected derivatives were investigated by using ¹H? ¹⁵N chemical shift correlation techniques. To map the influence of sugar moiety on the directly bonded nitrogen atom, selected N⁹‐glucosides and their ribose analogs were compared. Characteristic long‐range ¹H? ¹⁵N coupling constants, measured by using ¹H? ¹⁵N gradient‐selected single‐quantum multiple bond correlation (GSQMBC), are also reported and discussed. All compounds investigated here belong to cytokinins, an important group of plant hormones. Copyright © 2010 John Wiley & Sons, Ltd.     

Structural elucidation and NMR assignments of four aromatic lactones from a mangrove endophytic fungus (No. GX4‐1B)

Two new aromatic lactones, 6‐hydroxy‐4‐hydroxymethyl‐8‐methoxy‐3‐ methylisocoumarin (1) and 1,10‐dihydroxy‐8‐methyl‐dibenz[b, e]oxepin‐6,11‐dione (2), together with two known compounds, 1,10‐dihydroxy‐dibenz[b, e]oxepin‐6,11‐dione (3) and 3‐hydroxymethyl‐6,8‐dimethoxycoumarin (4), were isolated from a mangrove endophytic fungus (No. GX4‐1B) collected from the South China Sea. Their structures were elucidated and the data of ¹H and ¹³C NMR were assigned completely by HREIMS, 1D and 2D NMR experiments including HMQC, HMBC and NOESY. Copyright © 2010 John Wiley & Sons, Ltd.     

Design of two series of 1:1 cocrystals involving 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine and carboxylic acids

Two series of a total of ten cocrystals involving 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine with various carboxylic acids have been prepared and characterized by single‐crystal X‐ray diffraction. The pyrimidine unit used for the cocrystals offers two ring N atoms (positions N1 and N3) as proton‐accepting sites. Depending upon the site of protonation, two types of cations are possible [Rajam et al. (2017). Acta Cryst. C 73 , 862–868]. In a parallel arrangement, two series of cocrystals are possible depending upon the hydrogen bonding of the carboxyl group with position N1 or N3. In one series of cocrystals, i.e. 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–3‐bromothiophene‐2‐carboxylic acid (1/1), 1 , 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–5‐chlorothiophene‐2‐carboxylic acid (1/1), 2 , 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–2,4‐dichlorobenzoic acid (1/1), 3 , and 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–2‐aminobenzoic acid (1/1), 4 , the carboxyl hydroxy group (–OH) is hydrogen bonded to position N1 (O—H…N1) of the corresponding pyrimidine unit (single point supramolecular synthon). The inversion‐related stacked pyrimidines are doubly bridged by the carboxyl groups via N—H…O and O—H…N hydrogen bonds to form a large cage‐like tetrameric unit with an R₄²(20) graph‐set ring motif. These tetrameric units are further connected via base pairing through a pair of N—H…N hydrogen bonds, generating R₂²(8) motifs (supramolecular homosynthon). In the other series of cocrystals, i.e. 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–5‐methylthiophene‐2‐carboxylic acid (1/1), 5 , 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–benzoic acid (1/1), 6 , 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–2‐methylbenzoic acid (1/1), 7 , 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–3‐methylbenzoic acid (1/1), 8 , 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–4‐methylbenzoic acid (1/1), 9 , and 4‐amino‐5‐chloro‐2,6‐dimethylpyrimidine–4‐aminobenzoic acid (1/1), 10 , the carboxyl group interacts with position N3 and the adjacent 4‐amino group of the corresponding pyrimidine ring via O—H…N and N—H…O hydrogen bonds to generate the robust R₂²(8) supramolecular heterosynthon. These heterosynthons are further connected by N—H…N hydrogen‐bond interactions in a linear fashion to form a chain‐like arrangement. In cocrystal 1 , a Br…Br halogen bond is present, in cocrystals 2 and 3 , Cl…Cl halogen bonds are present, and in cocrystals 5 , 6 and 7 , Cl…O halogen bonds are present. In all of the ten cocrystals, π–π stacking interactions are observed.     

Synthesis,structural characterization and antimicrobial activity of mixed aryl–alkyl diorganotin(IV) compounds with quinoline‐2‐carboxylate (L−): {RR′SnLCl}n and RR′SnL2

A series of unsymmetrical diorganotin derivatives of quinoline‐2‐carboxylic acid (LH), namely polymeric {MePhSnClL}_n (1) and {EtPhSnClL}_n (2), and mononuclear MePhSnL₂ (3) and EtPhSnL₂ (4), was synthesized by the reaction of LH with the MePhSnCl₂, EtPhSnCl₂, MePhSnO, and EtPhSnO precursors, respectively. The compounds were characterized by elemental analysis and infrared spectroscopy, as well as by ¹ H, ¹³ C and ¹¹⁹Sn NMR. The molecular structures of representative compounds 2 and 4 were determined by single‐crystal X‐ray crystallography. This study showed that polymeric 2 adopts a distorted octahedral geometry as the carboxylate ligand N,O chelates an Sn atom and at the same time bridges a neighbouring Sn atom via the second O atom, with the remaining sites being occupied by the Cl and two C atoms; the O atoms are trans to each other. The result of the μ₂‐bridging mode of L^? is the formation of a supramolecular helical chain. Compound 4 adopts a skew‐trapezoidal bipyramidal geometry with the organo groups lying over the plane of the two N,O‐chelating carboxylate ligands and being directed over the weaker Sn―N bonds. The in vitro antimicrobial activities of 1–4 against a Gram‐positive bacteria strain (Bacillus subtilis), a Gram‐negative bacteria strain (Escherichia coli) and against Candida albicans were studied and compared with the antimicrobial activities of Ph₂SnL₂ and Me₂SnL₂, and with the antimicrobial standards gentamicin, tetracycline, ampicillin and penicillin. All organotin compounds displayed remarkable antibacterial activities that were comparable to those of the standard drugs, in particular against B. subtilis, where the activity was correlated with the number of Cl substituents. Copyright © 2012 John Wiley & Sons, Ltd.