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In this work, the synthesis of BODIPY-phenyl-triazole labelled coumarins (BPhTCs) using a two-step approach is described. The influence of the BODIPY appending on the photophysical, electrochemical and thermal properties of the phenyl-triazole-coumarin precursors (PhTCs) was investigated. Band gap energies were measured by absorption spectroscopy (2.20 ± 0.02 eV in the solid and 2.35 ± 0.01 eV in solution) and cyclic voltammetry (2.10 ± 0.05 eV). The results are supported by DFT calculations confirming the presence of lowest LUMO levels that facilitate the electron injection and stabilize the electron transport. Their charge-transport parameters were measured in Organic Field-Effect Transistor (OFET) devices. BPhTCs showed an ambipolar transistor behavior with good n-type charge mobilities (10 -2 cm 2 V -1 s -1 ) allowing these derivatives to be employed as promising semiconducting crystalline and fluorescent materials with good thermal and air stability up to 250 °C., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Itzia Irene Padilla-Martinez reports financial support was provided by National Council on Science and Technology (CONACYT now CONAHCYT, National Council on Humanities, Science and Technology), Mexico. Norberto Farfan reports financial support was provided by National Council on Science and Technology, Mexico. Jose Emilio de la Cerda-Pedro reports financial support was provided by National Council on Science and Technology, Mexico. Oscar Javier Hernandez-Ortiz reports financial support was provided by National Council on Science and Technology, Mexico. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Ltd.)

(Thio)ureas ((T)Us) and benzothiazoles (BTs) each have demonstrated to have a great variety of biological activities. When these groups come together, the 2-(thio)ureabenzothizoles [(T)UBTs] are formed, improving the physicochemical as well as the biological properties, making these compounds very interesting in medicinal chemistry. Frentizole, bentaluron and methabenzthiazuron are examples of UBTs used for treatment of rheumatoid arthritis and as wood preservatives and herbicides in winter corn crops, respectively. With this antecedent, we recently reported a bibliographic review about the synthesis of this class of compounds, from the reaction of substituted 2-aminobenzothiazoles (ABTs) with iso(thio)cyanates, (thio)phosgenes, (thio)carbamoyl chlorides, 1,1'-(thio)carbonyldiimidazoles, and carbon disulfide. Herein, we prepared a bibliographic review about those features of design, chemical synthesis, and biological activities relating to (T)UBTs as potential therapeutic agents. This review is about synthetic methodologies generated from 1968 to the present day, highlighting the focus to transform (T)UBTs to compounds containing a range substituents, as illustrated with 37 schemes and 11 figures and concluded with 148 references. In this topic, the scientists dedicated to medicinal chemistry and pharmaceutical industry will find useful information for the design and synthesis of this interesting group of compounds with the aim of repurposing these compounds.

Benzimidazole (BI) and its derivatives are interesting molecules in medicinal chemistry because several of these compounds have a diversity of biological activities and some of them are even used in clinical applications. In view of the importance of these compounds, synthetic chemists are still interested in finding new procedures for the synthesis of these classes of compounds. Astemizole (antihistaminic), Omeprazole (antiulcerative), and Rabendazole (fungicide) are important examples of compounds used in medicinal chemistry containing BI nuclei. It is interesting to observe that several of these compounds contain 2-aminobenzimidazole (2ABI) as the base nucleus. The structures of 2ABI derivatives are interesting because they have a planar delocalized structure with a cyclic guanidine group, which have three nitrogen atoms with free lone pairs and labile hydrogen atoms. The 10-π electron system of the aromatic BI ring conjugated with the nitrogen lone pair of the hexocyclic amino group, making these heterocycles to have an amphoteric character. Synthetic chemists have used 2ABI as a building block to produce BI derivatives as medicinally important molecules. In view of the importance of the BIs, and because no review was found in the literature about this topic, we reviewed and summarized the procedures related to the recent methodologies used in the N-substitution reactions of 2ABIs by using aliphatic and aromatic halogenides, dihalogenides, acid chlorides, alkylsulfonic chlorides, carboxylic acids, esters, ethyl chloroformates, anhydrides, SMe-isothioureas, alcohols, alkyl cyanates, thiocyanates, carbon disulfide and aldehydes or ketones to form Schiff bases. The use of diazotized 2ABI as intermediate to obtain 2-diazoBIs was included to produce Nsubstituted 2ABIs of pharmacological interest. Some commentaries about their biological activity were included., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Benzimidazole is an important heterocyclic fragment, present in many biologically active compounds with a great variety of therapeutic purposes. Most of the benzimidazole activities are explained through the existence of 1,3-tautomeric equilibrium. As the binding affinity of each tautomer to a protein target depends on an established bioactive conformation, the effect of tautomers on the ligand protein binding mechanism is determinant. In this work, we searched and analyzed a series of reported 13 C-NMR spectra of benzazoles and benzazolidine-2-thiones with the purpose of estimating their tautomeric equilibrium. Herein, several approaches to determine this problem are presented, which makes it a good initial introduction to the non-expert reader. This chemical shift difference and C4/C7 signals of benzimidazolidine-2-thione and 1-methyl-2-thiomethylbenzimidazole as references were used in this work to quantitatively calculate, in solution, the pyrrole-pyridine tautomeric ratio in equilibrium. The analysis will help researchers to correctly assign the chemical shifts of benzimidazoles and to calculate their intracyclic or exocyclic tautomeric ratio as well as mesomeric proportion in benzimidazoles.

The (thio)urea and benzothiazole (BT) derivatives have been shown to have a broad spectrum of biological activities. These groups, when bonded, result in the 2-(thio)ureabenzothizoles (TBT and UBT), which could favor the physicochemical and biological properties. UBTs and TBTs are compounds of great importance in medicinal chemistry. For instance, Frentizole is a UBT derivative used for the treatment of rheumatoid arthritis and systemic lupus erythematosus. The UBTs Bentaluron and Bethabenthiazuron are commercial fungicides used as wood preservatives and herbicides in winter corn crops. On these bases, we prepared this bibliography review, which covers chemical aspects of UBTs and TBTs as potential therapeutic agents as well as their studies on the mechanisms of a variety of pharmacological activities. This work covers synthetic methodologies from 1935 to nowadays, highlighting the most recent approaches to afford UBTs and TBTs with a variety of substituents as illustrated in 42 schemes and 13 figures and concluded with 187 references. In addition, this interesting review is designed on chemical reactions of 2-aminobenzothiazoles (2ABTs) with (thio)phosgenes, iso(thio)cyanates, 1,1'-(thio)carbonyldiimidazoles [(T)CDI]s, (thio)carbamoyl chlorides, and carbon disulfide. This topic will provide information of utility for medicinal chemists dedicated to the design and synthesis of this class of compounds to be tested with respect to their biological activities and be proposed as new pharmacophores.

Nowadays, organic chemists are interested in the field of heterocyclic chemistry due to its use in the synthesis of a great variety of biologically active compounds. Heterocyclic compounds are widely found in nature and are essential for life. Among these, some natural nitrogen containing heterocyclic compounds have been used as chemotherapeutic agents. Their attachment to sugar molecules either as thioglycosides or as nucleosides analogues plays an important role in vital biological processes as well as in synthetic organic chemistry. Molecules containing benzothiazole (BT) nuclei are of this interesting class of compounds because some of them have been found to have a wide variety of biological activities. In this sense, we selected this topic to review and to then summarize the procedures related to the condensation reactions of o -aminothiophenoles (ATPs) as well as their disulfides with carboxylic acids, esters, orthoesters, acyl chlorides, amides, and nitriles. The condensation reactions with carbon dioxide (CO 2 ) are included. Conventional methods with the use of acid and metal catalysts as well as recent green techniques, such as microwave irradiation, the use of ionic liquids, and ultrasound (US) chemistry, which have proven to have many advantages, were found in the review.

A new organic salt of metformin, an antidiabetic drug, and N , N '-(1,4-phenylene)dioxalamic acid, was mechanochemically synthesized, purified by crystallization from solution and characterized by single X-ray crystallography. The structure revealed a salt-type crystal hydrate composed of one dicationic metformin unit, two monoanionic units of the acid and four water molecules, namely H 2 Mf(HpOXA) 2 ∙4H 2 O. X-ray powder, IR, 13 C-CPMAS, thermal and BET adsorption-desorption analyses were performed to elucidate the structure of the molecular and supramolecular structure of the anhydrous microcrystalline mesoporous solid H 2 Mf(HpOXA) 2 . The results suggest that their structures, conformation and hydrogen bonding schemes are very similar. To the best of our knowledge, the selective formation of the monoanion HpOXA - , as well as its structure in the solid, is herein reported for the first time. Regular O(δ-)∙∙∙C(δ), O(δ-)∙∙∙N + and bifacial O(δ-)∙∙∙C(δ)∙∙∙O(δ-) of n→π * charge-assisted interactions are herein described in H 2 MfA organic salts which could be responsible of the interactions of metformin in biologic systems. The results support the participation of n→π * charge-assisted interactions independently, and not just as a short contact imposed by the geometric constraint due to the hydrogen bonding patterns.

Being the base of several non-communicable diseases, including cancer, inflammation is a complex process generated by tissue damage or change in the body homeostatic state. Currently, the therapeutic treatment for chronic inflammation related diseases is based on the use of selective cyclooxygenase II enzyme, COX-2, inhibitors or Coxibs, which have recently regained attention giving their preventive role in colon cancer. Thus, the discovery of new molecules that selectively inhibit COX-2 and other inflammatory mediators is a current challenge in the medicinal chemistry field. 1-Phenylbenzimidazoles have shown potential COX inhibitory activity, because they can reproduce the interaction profile of known COX inhibitors. Therefore, in the present investigation a series of 1,2-diphenylbenzimidazoles (DPBI) with different aromatic substitutions in the para position were synthesized and their interaction with COX-2 and nitric oxide synthase, iNOS, was determined in silico, in vitro and in vivo. Compound 2-(4-bromophenyl)-1-(4-nitrophenyl)-1H-benzo[d]imidazole showed the best inhibition towards COX-2, while compounds N-(4-(2-(4-bromophenyl)-1H-benzo[d]imidazol-1-yl)phenyl)acetamide and N-(4-(2-(4-chlorophenyl)-1H-benzo[d]imidazol-1-yl)phenyl)acetamide diminished the production of NO in vitro. Additionally, they had a significant anti-inflammatory activity in vivo when given orally., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

In this investigation, the reaction of 2-dithiomethylcarboimidatebenzothiazole with a series of six chiral amino-acids was studied. The reaction proceeds through the isolable sodium salt of SMe-isothiourea carboxylates as intermediates, whose reaction with methyl iodide in stirring DMF as solvent affords SMe-isothiourea methyl esters. The presence of water in the reaction leads to the corresponding urea carboxylates as isolable intermediates, whose methyl esters were obtained. Finally, the urea N -methyl amide derivatives were isolated when SMe-isothiourea or urea methyl esters were reacted with methylamine in the presence of water. The structures of synthesized compounds were established by 1 H and 13 C nuclear magnetic resonance and the structures of SMe-isothiourea methyl esters derived from ( l )-glycine, ( l )-alanine, ( l )-phenylglycine, and ( l )-leucine, by X-ray diffraction analysis. This methodology allows to functionalize 2-aminobenzothiazole with SMe-isothiourea, urea, and methylamide groups derived from chiral amino acids to get benzothiazole derivatives containing coordination sites and hydrogen bonding groups. Further research on the biological activities of some of these derivatives is ongoing.

A detailed structural analysis of the benzimidazole nitroarenes 1-(4-nitrophenyl)-1H-1,3-benzimidazole, C 13 H 9 N 3 O 2 , (I), 1-(4-nitrophenyl)-2-phenyl-1H-1,3-benzimidazole, C 19 H 13 N 3 O 2 , (II), and 2-(3-methylphenyl)-1-(4-nitrophenyl)-1H-1,3-benzimidazole, C 20 H 15 N 3 O 2 , (III), has been performed. They are nonplanar structures whose crystal arrangement is governed by Csp 2 -H...A (A = NO 2 , N py and π) hydrogen bonding. The inherent complexity of the supramolecular arrangements of compounds (I) (Z' = 2) and (II) (Z' = 4) into tapes, helices and sheets is the result of the additional participation of π-π NO2 and n-π* (n = O and N py ; π* = Csp 2 and N NO2 ) interactions that contribute to the stabilization of the equi-energetic conformations adopted by each of the independent molecules in the asymmetric unit. In contrast, compound (III) (Z' = 1) is self-paired, probably due to the effect of the steric demand of the methyl group on the crystal packing. Theoretical ab initio calculations confirmed that the presence of the arene ring at the benzimidazole 2-position increases the rotational barrier of the nitrobenzene ring and also supports the electrostatic nature of the orthogonal ONO...Csp 2 and N py ...NO 2 interactions.

The solventless synthesis of tris(pyrazolyl)phenylmethane ligands of formula C₆H₅C(Pz R2 )₃ (R = H, Me), starting from PhCCl₃ and 3,5-dimethylpyrazole (Pz Me2 ) or pyrazole (Pz) was performed. The sterically crowded C₆H₅C(Pz Me2 )₃ is thermally transformed into the bis(pyrazolyl)( p -pyrazolyl)phenylmethane ligand Pz Me2 -C₆H₄CH(Pz Me2 )₂. In this compound both Pz Me2 rings are linked through the N-atom to the methine C-atom. At higher temperatures, the binding mode of Pz Me2 changes from N1 to C4. All transformations occurred via quinonoid carbocation intermediates that undergo an aromatic electrophilic substitution on the 4-position of Pz Me2 . Reaction conditions were established to obtain five tris(pyrazolyl)phenylmethane ligands in moderate to good yields. ¹H- and 13 C-NMR spectroscopy and X-ray diffraction of single crystals support the proposed structures.

Two new molecular structures, namely 1,3-bis(trimethylsilyl)-1H-benzimidazole-2(3H)-thione, C13H22N2SSi2, (2), and 1-trimethylsilyl-1H-benzimidazole-2(3H)-thione, C10H14N2SSi, (3), are reported. Both systems were derived from 1H-benzimidazole-2(3H)-thione. Noncovalent C-H···π interactions between the centroid of the benzmidazole system and the SiMe3 groups form helicoidal arrangements in (2). Dimerization of (3) results in the formation of R2(2)(8) rings via N-H···S interactions, along with parallel π-π interactions between imidazole and benzene rings.

The title compound, C12H13NO4, is one of the few examples that exhibits a syn conformation between the amide and ester carbonyl groups of the oxalyl group. This conformation allows the engagement of the amide H atom in an intramolecular three-centred hydrogen-bonding S(6)S(5) motif. The compound is self-assembled by C=O...C=O and amide-π interactions into stacked columns along the b-axis direction. The concurrence of both interactions seems to be responsible for stabilizing the observed syn conformation between the carbonyl groups. The second dimension, along the a-axis direction, is developed by soft C-H...O hydrogen bonding. Density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) level of theory were performed to support the experimental findings.

Intramolecular hydrogen bond (HB) formation was analyzed in the model compounds N-(2-benzoylphenyl)acetamide, N-(2-benzoylphenyl)oxalamate and N1,N2-bis(2-benzoylphenyl)oxalamide. The formation of three-center hydrogen bonds in oxalyl derivatives was demonstrated in the solid state by the X-ray diffraction analysis of the geometric parameters associated with the molecular structures. The solvent effect on the chemical shift of H6 [δH6(DMSO-d6)-δH6(CDCl3)] and Δδ(ΝΗ)/ΔT measurements, in DMSO-d6 as solvent, have been used to establish the energetics associated with intramolecular hydrogen bonding. Two center intramolecular HB is not allowed in N-(2-benzoylphenyl)acetamide either in the solid state or in DMSO-d6 solution because of the unfavorable steric effects of the o-benzoyl group. The estimated ΔHº and ΔSº values for the hydrogen bonding disruption by DMSO-d6 of 28.3(0.1) kJ·mol-1 and 69.1(0.4) J·mol-1·K-1 for oxalamide, are in agreement with intramolecular three-center hydrogen bonding in solution. In the solid, the benzoyl group contributes to develop 1-D and 2-D crystal networks, through C-H∙∙∙A (A = O, π) and dipolar C=O∙∙∙A (A = CO, π) interactions, in oxalyl derivatives. To the best of our knowledge, this is the first example where three-center hydrogen bond is claimed to overcome steric constraints.

The reactions of the benzimidazole nitrogen atoms and the exocyclic amino group of 2-aminobenzimidazole with CS2 in NaOH basic medium followed by methylation with methyl iodide was explored. With careful control of the stoichiometric quantities and addition sequences, this set of reactions allows the selective functionalization of the benzimidazole ring with N-dithiocarbamate, S-methyldithiocarbamate or dimethyl- dithiocarboimidate groups. The products were characterized by 1H-, 13C-NMR spectroscopy and three of them by X-ray diffraction analysis. The preferred isomers, tautomers and conformers were established.

In the title compound, C(24)H(36)N(6)O(6)·C(2)H(6)OS, the carbonyl groups are in an antiperiplanar conformation, with O=C-C=O torsion angles of 178.59 (15) and -172.08 (16)°. An intramolecular hydrogen-bonding pattern is depicted by four N-H...O interactions, which form two adjacent S(5)S(5) motifs, and an N-H...N interaction, which forms an S(6) ring motif. Intermolecular N-H...O hydrogen bonding and C-H...O soft interactions allow the formation of a meso-helix. The title compound is the first example of a helical 1,2-phenylenedioxalamide. The oxalamide traps one molecule of dimethyl sulfoxide through N-H...O hydrogen bonding. C-H...O soft interactions give rise to the two-dimensional structure.

In the title complex salt, [Ir(C(5)H(4)O)(C(16)H(22)N(6))(CO)](CF(3)O(3)S), the Ir(III) centre adopts a distorted octahedral geometry with a facial coordination of the tris(3,5-dimethyl-1H-pyrazol-1-yl)methane ligand. The C-C distances of the iridacycle are in agreement with its iridacyclohexa-2,5-dien-4-one nature, which presents a nonsymmetric boat-like conformation with the C-Ir-C vertex more bent than the C-C(=O)-C vertex. The supramolecular architecture is mainly directed by CO...CO and CO...π and Csp(3)-H...O interactions, the arrangement of which depends on the anion.

Symmetric and non-symmetric 2-(N-H, N-methyl, N-ethylenyl and N-aryl)guanidinebenzothiazoles were synthesized from the reaction of ammonia, methylamine, pyrrolidine and aniline with dimethyl benzo[d]thiazol-2-yl-carbonodithioimidate as intermediate. The products were characterized by ¹H-, ¹³C-NMR spectroscopy and three of them by X-ray diffraction analysis. HN-phenyl protons formed intramolecular hydrogen bonds that assist the stereochemistry of the second substituent, whereas the HN-alkyl protons were involved in intermolecular hydrogen bonding.

In the title compound, C(31)H(38)O(17), the 1,3-dioxane and pyran-oside rings both show (4)C(1) chair conformations while for the d-fructofuran-oside moiety an envelop 3E conformation is observed. The phenyl ring is oriented almost perpendicular to the 1,3-dioxane ring [dihedral angle = 79.3 (2)°], and the acetate groups are equatorial for the pyran-oside ring and axial for the furan-oside ring. The analysis of potential hydrogen bonds shows both intra- and inter-molecular C-H⋯O contacts to be present.

In the title compound, C(16)H(18)N(4)O(2), the two carbonyl groups are in an anti-periplanar conformation with an O=C-C=O torsion angle of 173.86 (17)°. In the crystal, a pair of inter-molecular N-H⋯O hydrogen bonds, forming an R(2) (2)(10) ring motif, connect the mol-ecules into an inversion dimer. The dimers are further linked by N-H⋯N and C-H⋯π inter-actions, forming a zigzag chain along the b axis.

The thermal [4+2] cycloadditions of 3-acetyl-, 3-carbamoyl, and 3-ethoxycarbonylcoumarins with 2,3-dimethyl-1,3-butadiene under solvent free conditions are reported, as well as the epoxidation reactions of some adducts. Discussion is focused on the structural features of the Diels-Alder adducts and their epoxides, based upon NMR, X-ray, and mass spectral data, and supported by ab initio theoretical calculations.

The title Schiff base compound, 4-nitro-1-oxo-2-{(E)-[2-(piperidin-1-yl)ethyl]iminiomethyl}cyclohexadienide, C(14)H(19)N(3)O(3), exists as a zwitterion, with the H atom of the phenol group being transferred to the imine N atom. The C=O, C(Ar)-C(Ar) and C-N bond lengths are in agreement with the oxocyclohexadienide-iminium zwitterionic form. The iminium H atom is engaged in a strong intramolecular hydrogen bond with the O atom of the keto group (N(+)-H...O) to form an S(6) motif. Soft C-H...O interactions in the ac plane lead to the development of hydrogen-bonded tapes, which are pi-stacked through the oxocyclohexadienide ring and iminium group. The significance of this study is in providing crystallographic evidence, supported by NMR and IR data, of the predominance of the oxocyclohexadienide-iminium zwitterion form over the noncharged canonical form in the title Schiff base.

The title compounds, C(12)H(9)ClO(4), (I), and C(12)H(9)BrO(4), (II), are isomorphous and crystallize in the monoclinic space group P2(1)/c. Both compounds present an anti conformation between the 3-carboxy and the lactone carbonyl groups. Both carbonyl groups are out of the plane defined by the remaining chromene atoms, by 8.37 (6) and 17.57 (6) degrees for (I), and by 9.07 (8) and 18.96 (18) degrees for (II), owing to their involvement in intermolecular interactions. In both compounds, layers of centrosymmetric hydrogen-bonded dimers are developed in the [-5 -2 22] plane through C-H...O interactions, involving both carbonyl groups as acceptors. Two families of dimers stack through C=O...C=O, C=O...pi and C-X...C=O (X = Cl and Br) dipolar interactions, as well as a C-H...pi interaction, developing the three-dimensional structure along the c axis.

The molecular and supramolecular structures of 2-(1,3-dioxo-2,3,3a,4,7,7a-hexahydro-1H-isoindol-2-yl)phenyl acetate, C16-H15NO4, (I), and its para isomer, 4-(1,3-dioxo-2,3,3a,4,7,7a-hexahydro-1H-isoindol-2-yl)phenyl acetate, (II), are reported. The torsion angle between the succinimide and benzene rings depends on the position of the acetoxy substitution [89.7 (1) and 61.9 (1) degrees for (I) and (II), respectively]. The twist of the acetoxy group relative to the mean plane of the benzene ring is almost independent of the acetoxy position [66.0 (1) and 70.0 (1) degrees ]. Packing interactions for both compounds include soft C-H...X (X = O and Ph) interactions, forming chains of centrosymmetric dimers and interlinked chains for (I) and (II), respectively. In addition, three perpendicular dipole C=O...C=O interactions contribute to the supramolecular structure of (II).

The ethyl oxamate group, N-C(O)-C(O)-OEt, in the title compound, alternatively called diethyl N,N':N,N'-bis(ethylene)dioxamate, C12H18N2O6, can be considered as being composed of two singly bonded amide and ester functionalities. The ethyl oxamate group is not planar. The two carbonyl groups are almost perpendicular, with an oxalyl O=C-C=O torsion angle of -111.34 (17) degrees. The molecule is located on an inversion centre. Infinite supramolecular tapes, propagating along the b axis, are formed through soft C-H...O interactions which form a centrosymmetric R(2)2(12) motif.

The title compound, C16H19NO5, crystallizes as a centrosymmetric dimer through strong O-H...O hydrogen-bonding interactions between the hydroxyphenyl and morpholinocarbonyl groups. The morpholinocarbonyl group is almost perpendicular to the propenoate moiety. Electron delocalization in the N-C(=O) fragment leads to the formation of hydrogen-bonded S(5) ring motifs through C-H...O interactions.

In exo-2-(3,5-dioxo-10-oxa-4-azatricyclo[5.2.1.0(2,6)]dec-8-en-4-yl)phenyl acetate, C(16)H(13)NO(5), the plane of the acetoxy group lies almost perpendicular to that of the phenyl ring [dihedral angle = 89.8 (1) degrees ], in contrast with the smaller deviations found in the para isomer exo-4-(3,5-dioxo-10-oxa-4-azatricyclo[5.2.1.0(2,6)]dec-8-en-4-yl)phenyl acetate, C(16)H(13)NO(5), these being 63.6 (1) and 37.0 (1) degrees for the two crystallographically independent molecules. Irrespective of the position of the acetoxy group, both compounds pack through soft C-H.X (X is O or phenyl) interactions, forming interlinked centrosymmetric tetramers in the bc plane.