Insecticidal and α-glucosidase inhibitory activities of chemical constituents from Viburnum fordiae Hance

The ethanolic extract of the stems of Viburnum fordiae Hance showed insecticidal and α-glucosidase inhibitory activities and then was fractionated by bioactivity-guided fractionation to obtain a rare C₁₃-norisoprenoid (1), together with a new phenolic glycoside (2), and seven known compounds, alangionoside C (3), pisumionoside (4), koaburaside (5), 3,5-dimethoxy-benzyl alcohol 4-O-β-d-glucopyranoside (6), 3,4,5-trimethoxybenzyl-β-d-glucopyranoside (7), arbutin (8), and salidroside (9). The previously undescribed compounds were elucidated as (3R,9R)-3-hydroxy-7,8-didehydro-β-ionyl 9-O-α-d-arabinopyranosyl-(1→6)-β-d-glucopyranoside (1) and 2-(4-O-β-d-glucopyranosyl)syringylpropane-1,3-diol (2) by spectroscopic data (¹H and ¹³C NMR, HSQC, HMBC, ¹H-¹H COSY, HSQC-TOCSY, HRESIMS, IR and ORD) and chemical methods. Compound 1 showed potent insecticidal effect against Mythimna separata with LD₅₀ value of 140 μg g^?1. Compounds 2, 5, 6, 8 and 9 showed varying α-glucosidase inhibitory activity with IC₅₀ values ranging from 148.2 to 230.9 μM.     

Ruthenium(II) carbonyl complexes of P,P and P,O donor diphosphine ligands,Ph2P(CH2)nPPh2 and Ph2P(CH2)nP(O)Ph2, n = 2, 3 and their activities in catalytic transfer hydrogenation reactions

The polymeric precursor [RuCl₂(CO)₂]_n reacts with the ligands, P∩P (a, b) and P∩O (c, d), in 1:1 M ratio to generate six-coordinate complexes [RuCl₂(CO)₂(?²-P∩P)] (1a, 1b) and [RuCl₂(CO)₂(?²-P∩O)] (1c, 1d), where P∩P: Ph₂P(CH₂)_nPPh₂, n = 2(a), 3(b); P∩O: Ph₂P(CH₂)_nP(O)Ph₂, n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR, and NMR spectroscopy. 1a–1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75–290 h^?1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl₃ itself. Among 1a–1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogs (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b, and 1d decrease considerably, while 1c shows similar activity during the second run.     

Synthesis and characterization of water-soluble arene-ruthenium complexes and their application in biphasic olefin oxidation

New water-soluble complexes [(η⁶-C₆H₆)RuCl(C₅H₄N-2-CH?=?N-R)]Cl (1) (with R?=?4-hydroxymethylphenyl (a), 2,4-dichlorophenyl (b), 2-fluorophenyl (c), 3-carboxyphenyl (d)) have been synthesized by reacting [(η⁶-C₆H₆)Ru(μ-Cl)Cl]₂ with the N,N′-bidentate ligands in a 1:2 ratio. Full characterization of all complexes was accomplished using ¹H and ¹³C NMR, elemental analyses, UV-Vis spectroscopy, IR spectroscopy and single crystal X-ray crystallography for determination of the structure of 1d, as 1d·4H₂O. The single crystal structure confirmed coordination of the ligand to the ruthenium(II) center leading to a structure commonly described as a pseudo-octahedral, three-legged piano stool. The geometry around the Ru(II) center is such that the arene ring occupies the apex of the stool while the N,N′-bidentate ligand and a chloride occupy the base of the stool. The synthesized Ru(II) complexes were tested as catalysts for oxidation of styrene using NaIO₄ as a co-oxidant in a biphasic system. All complexes were active, giving good yields of benzaldehyde. Catalyst 1c was later investigated for olefin oxidation and gave high yields of the corresponding aldehydes as the major products in all cases.     

Lebbeckoside C,a new triterpenoid saponin from the stem barks of Albizia lebbeck inhibits the growth of human glioblastoma cells

One new acacic acid-type saponin, named lebbeckoside C (1), was isolated from the stem barks of Albizia lebbeck. Its structure was established on the basis of extensive analysis of 1D and 2D NMR (¹H, ¹³C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as 3-O-[β-d-xylopyranosyl-(l→2)-β-d-fucopyranosyl-(1→6)-[β-d-glucopyranosyl(1→2)]-β-d-glucopyranosyl]-21-O-{(2E,6S)-6-O-{4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-4-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl)octa-2,7-dienoyl]-β-d-quinovopyranosyl}-2,6-dimethylocta-2,7-dienoyl}acacic acid 28 O-[β-d-quinovopyranosyl-(l→3)-[α-l-arabinofuranosyl-(l→4)]-α-l-rhamnopyranosyl-(l→2)-β-d-glucopyranosyl] ester. The isolated saponin (1) displayed significant cytotoxic activity against the human glioblastoma cell line U-87 MG and TG1 stem-like glioma cells isolated from a patient tumor with IC₅₀ values of 1.69 and 1.44 μM, respectively.     

A new flavonol glycoside and other flavonoids from the aerial parts of Taverniera aegyptiaca

Isolation of flavonoids from the aerial parts of Taverniera aegyptiaca Bioss. (Fabaceae) led to identification of one new flavonol glycoside, isorhamnetin-3-O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside (1), along with eleven compounds, which previously have not been isolated from this plant quercetin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranoside] (2), isorhamnetin-3-O-α-l-arabinopyranoside (3), quercetin-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (4), isorhamnetin-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (7), isorhamnetin 3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranoside] (8), isorhamnetin 3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside] (9), kaempferol 3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)-β-d-galactopyranoside] (10), isorhamnetin (11), 4,4′-dihydroxy-2′-methoxychalcone (12), formononetin (13) and calycosin (15)] and some compounds already known from this plant [quercetin-3-O-robinobioside (5), isorhamnetin-3-O-robinobioside (6), afrormosin (14) and odoratin (16)].     

Chemical constituents of Genista numidica Spach aerial parts and their antimicrobial,antioxidant and antityrosinase activities

A previously undescribed triterpenoid saponin, 3-O-[α-l-rhamnopyranosyl-(1→2)-{β-d-glucopyranosyl-(1→6)-}β-d-galactopyranosyl-(1→2)-β-d-glucuronopyranosyl]-sophoradiol (1), in addition to twenty-nine known constituents (2–30) were isolated from the aerial parts of Genista numidica Spach. Structures elucidation was performed by comprehensive 1D- and 2D-NMR analyses and HRESIMS. The extracts, fractions and isolated compounds were evaluated for their antibacterial, antioxidant and tyrosinase inhibitory activities. The experimental findings indicated that genistin (16), isosalipurpol (27), and koaburaside (29) have moderate to low antibacterial activity against E. faecalis, S. aureus, S. epidermidis and P. aeruginosa bacteria with MICs ranging from 31.2 to 125 μg/mL. Compounds 19 and 27 exhibited a good antiradical activity potential (IC₅₀ 11.8 and 11.1 μg/mL, respectively). Only compounds 23, 27 and 28 exhibited low inhibitory effect against mushroom tyrosinase (IC₅₀ from 90.2 to 225.6 μg/mL).     

Synthesis and Characterization of Alkyltris(2-pyridyl)phosphonium Salts

Alkytris(2-pyridyl)phosphonium salts [(2-Py) ₃ PR]X 1 [1a, R = Et, X = Br; 1b, R = Pr, X = Br; 1c, R = Bu, X = Br; 1d, R = CH₂Ph, X = Br; 1e, R = CH ₂ Ph, X = Cl] were synthesised from (2-Py) ₃ P and an excess of RCl. 1c and 1e were found to rapidly decompose in hot acetone to 2,2′-bipyridinium(+1) bromide 2 and (2-Py)P(O)(CH ₂ Ph)C(OH)Me ₂ 3, respectively. A reaction mechanism for both products is proposed. All compounds were fully characterized, including X-ray crystallography for 1a and 3 with 1a being the first representative of this class of compounds characterized by this technique.     

Syntheses,crystal structures and fluorescent properties of four one-dimensional lanthanide coordination polymers with 3-cyanobenzoato

The hydrothermal reactions of Nd(ClO₄)₃·6H₂O, Gd(ClO₄)₃·6H₂O, Dy(ClO₄)₃·6H₂O, Er(ClO₄)₃·6H₂O with 1,3-dicyanobenzene, give rise to four one-dimensional rare earth-based coordination polymers: [M(3-CNC₆H₄COO)₃(H₂O)₂] _n (where M?=?Nd (1), Gd (2), Dy (3), Er (4), 3-CNC₆H₄COO?=?3-cyanobenzoato), respectively. Their solid-state structures have been characterized by X-ray single-crystal diffraction studies. The results show that 1,3-dicyanobenzene hydrolyzed to give 3-cyanobenzoato under hydrothermal condition, and the four complexes are isomorphous. Crystal data for 1: triclinic, space group P-1, a?=?9.4063(19), b?=?11.485(2), c?=?12.616(3)?Å, α?=?66.38(3), β?=?74.01(3), γ?=?86.96(3)°, V?=?1197.9(4)?ų, Z?=?1, D _c?=?1.704?Mg?m^?3; for 2: triclinic, space group P-1, a?=?9.3712(19), b?=?11.446(2), c?=?12.627(3)?Å, α?=?65.86(3), β?=?73.89(3), γ?=?86.84(3)°, V?=?1184.8(4)?ų, Z?=?1, D _c?=?1.759?Mg?m^?3; for 3: triclinic, space group P-1, a?=?9.3425(19), b?=?11.432(2), c?=?12.703(3)?Å, α?=?65.28(3), β?=?73.80(3), γ?=?86.86(3)°, V?=?1180.6(4)?ų, Z?=?1, D _c?=?1.780?Mg?m^?3; for 4: triclinic, space group P-1, a?=?9.3425(19), b?=?11.432(2), c?=?12.703(3)?Å, α?=?65.28(3), β?=?73.80(3), γ?=?86.86(3)°, V?=?1180.6(4)?ų, Z?=?1, D _c?=?1.7794?Mg?m^?3. The fluorescence emission spectra of compounds 1 to 4 are also reported.     

Tetrahedral manganese(II) complexes of 1-alkyl-2-(arylazo)imidazoles. X-ray crystal structure of [Mn(HaaiMe)4](ClO4)2·DMF (HaaiMe = 1-methyl-2-(phenylazo)imidazole)

[Mn(RaaiR′)₄](ClO₄)₂ complexes have been synthesised by reacting Mn(ClO₄)₂·6H₂O and RaaiR′ in methanol (RaaiR′?=?1-alkyl-2-arylazo)imidazole, R?=?H (a), Me (b), Cl (c); R′?=?Me (1), Et (2)). The orange–red crystalline compounds were characterised by microanalytical, spectroscopic, magnetic, thermal and electrochemical data. A single-crystal X-ray diffraction study of a DMF adduct of 1a revealed tetrahedral orientation of four ligands coordinating through imidazole-N while the azophenyl group (–N=N–Ph) is pendant. Cyclic voltammetry shows the Mn(III)/Mn(II) couple at >?1.0?V along with azo reductions.     

Structural determination of two new acacic acid-type saponins from the stem barks of Albizia zygia (DC.) J. F. Macbr

As a continuation of our interest in the study of triterpenoid saponins from Albizia zygia, phytochemical investigation of its stem barks led to the isolation of two new oleanane-type saponins, named zygiaosides C–D (1–2). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (1H-, 13C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as, 3-O-[ β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (1) and 3- O-[β-d-glucopyranosyl-(1→2) -[ β-d-fucopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (2).     

The chemical components of Coreopsis tinctoria Nutt. and their antioxidant,antidiabetic and antibacterial activities

Abstract

Seventeen compounds were isolated from the capitula of Coreopsis tinctoria Nutt. with various column chromatographic methods and semi-preparative HPLC. Their structures were identified by the spectroscopic data and comparison with literatures as 2′-hydroxy-4,4′-dimethoxy-chalcone; (1), isoliquiritigenin (2), eriodictyol (3), naringenin (4), maritimetin (5), butin (6), taxifolin (7), luteolin (8), 7,3′,4′-trihydroxyflavone (9), 8,3′,4′-trihydroxyflavone-7-O-β-d-glucoside (10), quercetin (11), quercetagitin-7-O-β-d-glucoside (12), quercetin-7-O-β-d-glucoside (13), 3,4-dihydroxybenzoic acid (14), caffeic acid (15), coreoside B (16), and myo-inositol (17). Compounds 1, 4, 9, 10 and 17 were isolated from C. tinctoria Nutt. for the first time. Compounds 7 and 12 possessed the highest antioxidant activity (IC₅₀?=?64.37 and 32.86?µg/ml, respectively) among the tested compounds (IC₅₀ value of positive control was 5.34?µg/ml). Compound 7 exhibited potent PTP1B enzymatic inhibition with an IC₅₀ value of 7.73?μg/ml (IC₅₀ value of positive control is 1.46?µg/ml). Furthermore, compound 5 showed strong antibacterial activity against the Gram-positive bacterium, S. aureus.     

A one-dimensional assembly of a Keggin tungstogermanate and sodium-pyridine-2-carboxylic acid: NaH3(C6H5N2)4[GeW12O40] · 7H2O

A hybrid inorganic-organic assembly, NaH₃(C₆H₅NO₂)₄[GeW₁₂O₄₀] ·?7H2O (1), has been synthesized and characterized by IR, UV, ¹H NMR and single crystal X-ray diffraction. Crystal data: orthorhombic, P2₁2₁2₁, a =?12.819(2) Å, b =?19.326(3) Å, c =?24.164(4) Å, V =?5986.4(18) ų, Z =?4, R ₁ =?0.0541 (I >?2σ). The structure of 1 is based on a 1D zigzag infinite chain assembled by alternating [GeW₁₂O₄₀]^4? and sodium-pyridine-2-carboxylic complex [Na(C₆H₅NO₂)3(H₂O)₂]⁺ via W–O_d–Na–O_d–W.     

Hydrothermal synthesis,structures and characterization of two new copper(II) triphosphonate compounds

Two copper(II) triphosphonate compounds, Cu[(APTPH₄)(phen)(H₂O)]?·?2.16H₂O (1) and [Cu(APTPH₄)(2,2′-bipy)(H₂O)]?·?2.63H₂O (2), have been prepared by a low temperature hydrothermal reaction from 1-aminopropane-1,1,3-triphosphonic acid (APTPH₆), CuO and a second ligand, phen?=?1,10-phenanthroline, or 2,2′-bipy?=?2,2′-bipyridyl. These two compounds were characterized by single crystal X-ray diffraction, elemental analysis, IR and TG. Crystal data for 1: Monoclinic, space group P2₁ /c, a?=?14.4830(7)?Å, b?=?9.1721(5)?Å, c?=?16.7403(8)?Å, β?=?90.101(2)°. For compound 2: Triclinic, space group P 1, a?=?7.1215(7)?Å, b?=?10.460(2)?Å, c?=?14.671(2)?Å, α?=?82.983(2)°, β?=?83.882(2)°, γ?=?80.617(2)°. In both compounds, each Cu²⁺ ion is five-coordinate with two oxygen atoms from the triphosphonate, two nitrogen atoms from the second ligand and one water molecule, to form a distorted square-pyramidal geometry. Both complexes have 3D supramolecular structures constructed by hydrogen bonds and π–π stacking interactions.     

Synthesis, spectral characterization and redox properties of iron (II) complexes of 1-alkyl-2-(arylazo)imidazole

Iron (II) complexes of 1-alkyl-2-(arylazo)imidazoles (p-R-C₆H₄-N=N-C₃H₂NN-1-R′, R = H (a), Me (b), Cl (c) and R′ = Me (1/3), Et (2/4) have been synthesized and formulated astris-chelates Fe(RaaiR′) ₃ ²⁺ . They are characterized by microanalytical, conductance, UV-Vis, IR, magnetic (polycrystalline state) data. The complexes are low spin in character,t _2g ⁶ (Fe(II)) configurations.     

Hydrothermal synthesis and crystal structure of a new two-dimensional zinc citrate complex

A new two-dimensional compound C₁₂H₁₄O₁₆Zn₃ (1), containing seven-coordinate zinc atoms was prepared by the hydrothermal technique. The compound obtained was characterized by TG-DTA, single crystal X-ray diffraction, elemental analysis and FT-IR analysis. Single-crystal X-ray diffraction analysis shows that compound 1 crystallizes with monoclinic symmetry in the space group P2₁/c, a?=?6.1552(13)?Å, b?=?14.546(3)?Å, c?=?9.581?Å, β?=?102.66(2)°, V?=?836.9(4)?ų, Z?=?2, R1?=?0.0311, wR2?=?0.0830.     

Photochemical reactions of group VIB metal carbonyls with heterocyclic Schiff bases derived from 4-amino -3-hydrazino-5-mercapto-1,2,4-triazole

The new complexes, M(CO)₅(Schiff base) [M?=?Cr; 1, Mo; 2, W; 3, Schiff base?=?4-salicylidenamino-3-hydrazino-5-mercapto-1,2,4-triazole, SAHMT, a; 4-(2-hydroxynaphthylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole, 2HNAHMT, b; 4-(3-hydroxybenzylidenamino)-3-hydrazino-5-mercapto-1,2,4- triazole, 3HBAHMT, c; 4-(4-hydroxybenzylidenamino)-3-hydrazino-5-mercapto-1,2,4- triazole, 4HBAHMT, d; 4-(5-bromosalicylidenamino)-3-hydrazino-5-mercapto-1,2,4-triazole, 5BrSAHMT, e; were synthesized by photochemical reaction of metal carbonyls M(CO)₆ (M?=?Cr, Mo, W) with new heterocyclic Schiff bases derived from 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, a–e. The ligands and complexes have been characterized by elemental analysis, EI-mass spectrometry, FT-IR, ¹H and ¹³C-{¹H}-NMR spectroscopy. The spectroscopic studies show that Schiff bases, a–e, are monodentate and coordinate via azomethine N donor to the central metal atom in M(CO)₅(Schiff base) (M?=?Cr, Mo, W).     

Dinuclear copper(II) complex and 1-D copper(II) complex with taurine Schiff base: synthesis,crystal structure,and properties

A dinuclear copper(II) compound, [Cu(btssb)(H₂O)]₂ · 4(H₂O) (1), and a 1-D chain copper(II) compound, [Cu(ctssb)(H₂O)] _n (2) [where H₂btssb is 2-[(5-bromo-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid and H₂ctssb is 2-[(3,5-dichloro-2-hydroxy-benzylidene)-amino]-ethanesulfonic acid], were prepared and characterized. Compound 1 crystallizes in the monoclinic space group P2₁/c, with a = 10.109(2) Å, b = 20.473(4) Å, c = 6.803(1) Å, β = 100.32(3)°, V = 1385.1(5) ų, and Z = 2; R ₁ for 1796 observed reflections [I > 2σ(I)] was 0.0357. The geometry around each copper(II) can be described as slightly distorted square pyramidal. The Cu^II ··· Cu^II distance is 5.471(1) Å. Compound 1 formed a 1-D network through O–H ··· O hydrogen bonds and 1-D water chains exist. The 1-D chain complex 2 crystallizes in the triclinic space group P 1, with a = 5.030(2) Å, b = 7.725(2) Å, c = 17.011(5) Å, α = 92.706(4)°, β = 97.131(4)°, γ = 102.452(3)°, V = 638.6(3) ų, and Z = 2; R ₁ for 1897 observed reflections [I > 2σ(I)] was 0.0171. In 2, Cu(II) was also a slightly distorted square pyramid formed by two oxygens and one nitrogen from ctssb, one oxygen from another ctssb, and one water molecule. The complex formed a 1-D chain through O–S–O bridge of ctssb ligand. The 1-D chain further constructed a double chain through O?H ··· O hydrogen bonds.     

Synthesis,spectral characterization and antibacterial activity of O,O’-dialkyl and alkylene dithiophosphatogold (III)dichloride; crystal structure of [S2POCMe2CMe2O]AuCl2

Abstract

O, O’-Dialkyl and alkylene dithiophosphatogold (III)dichloride complexes of the type [(RO)₂PS₂]AuCl₂ and [S₂POGO]AuCl₂, where R?=?Et, nPr, iPr, iBu, Ph, cyclohexyl and cyclopentyl, where G?=?CMe₂CMe₂-, have been synthesized in 80-90% yields by reaction of the corresponding acid or sodium salts of the appropriate dithiophosphoric acids in 1:1 ratio with gold (III) chloride in dry dichloromethane at room temperature. The compounds have been characterized by elemental analyses, IR and (¹H, ^l3C, and ³¹P) NMR. The crystal structure of [S₂POCMe₂CMe₂O]AuCl₂, was determined. These new complexes have shown their growth inhibiting potential against various bacterial strains with moderate to good activity.     

Two new compounds from the fruit of Ailanthus altissima

A new phenolic derivative, 4-hydroxyphenol-1-O-[6-O-(E)-feruloyl-β-d-glucopyranosyl]-(1→6)-β-d-glucopyranoside (1), and a new terpenylated coumarin, named altissimacoumarin H (2) were identified from the fruit of Ailanthus altissima (Mill.) Swingle (Simaroubaceae), together with ten known compounds (3–12), including two coumarins and eight phenylpropanoids. Their structures were determined on the basis of chemical method and spectroscopic data. Antiviral effect against Tobacco mosaic virus (TMV) of all the compounds obtained were evaluated using leaf-disc method.     

Crystal Structures of β‐1‐N‐Chloroacetamido Derivatives of d‐Glucose and d‐Galactose

Crystal structures of 1‐N‐(β‐d‐glucopyranosyl)chloroacetamide (1), an inhibitor of glycogen phosphorylase, and the corresponding galactopyranosyl amide (2) have been determined. Both crystals belong to P2₁2₁2₁ space group with 1 having the unit cell dimensions of a = 7.939(3), b = 9.547(3) and c = 14.157(2) Å, while those of 2 are, a = 7.636(10), b = 9.004(8) and c = 14.807(5) Å. The sugar ring takes a ⁴ C ₁ conformation and the amide linkage exists in Z‐anti conformation in both crystals. The torsion angle O5–C1–N1–C1′ is ? 93.9(5) for 1 and ? 111.5(3)° for 2. The conformational preference of Cl and N1 in 1 and 2 is found to be between anti and gauche. The molecular assembly in both 1 and 2 is stabilized by a finite chain of hydrogen bonds starting from N1H and ending at O1′, whereas a ten membered hydrogen‐bonded ring involving O4H and O5 is observed in 1.