Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• prepared scaffolds are valuable additions to the class of pyrazolo-1,2-benzothiazine antibiotics with selective antistaphylococcal activity. Keywords: acetamides; antibiotics; antimicrobial; benzothiazines; Staphylococcus aureus; Introduction The global crisis of antibiotic resistance has been

• complex as the amide coupling agent with thionyl chloride [38] (Figure 1C). Recently, benzothiazine scaffolds of phenyl acetamides were synthesized as potent inhibitors for ureolytic infections [39] (Figure 1D). Saccharine (a sweetener) was reported to be a potent carbonic anhydrase inhibitor (CAI) by

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• -6-yl)acetamides 5a–e. In 1H NMR spectra of the products, the characteristic signals for the protons of the methylene and methine fragments of the pyrimidine cycle are important in establishing the regiochemistry of the process. Thus, in the 1Н NMR spectra of compounds 4, the following reference

• -aryl-2-(7-oxo-5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidin-6-yl)acetamides 5a–e: A mixture of 2-aminoimidazole hemisulfate (1, 0.66 g, 5 mmol), N-arylitaconimide 3a–e (5 mmol), sodium acetate (0.82 g, 10 mmol), and iPrOH (10 mL) was boiled for 1 h. After cooling to rt, the resulting precipitate was

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• acetamides, which in turn outpaced carbamates [14]. In work by Michon and co-workers, a substrate survey in TCE at 80 °C revealed that tosylsulfonamide 1d was reactive, while the corresponding acetamide was not, and carbamates were seen as especially reactive, privileged substrates [8]. Our results are not

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• -dimethyl-1,4-dihydroisoquinoline-3(2H)-one, 4-bromoisoquinoline-1,3(2H,4H)-dione and two α-bromo(phenyl)acetamides were examined under various conditions (base, solvent, thiophile, temperature) and structure/medium features that influence product distribution (Eschenmoser coupling reaction, Hantzsch

• lactams 1, 2b, and 3 (i.e., cleavage of Ar–N bond or removal of >C(CH3)2 or >C=O bridge) leads to secondary α-bromo(phenyl)acetamides 4a and 4b. When α-bromoamide 4a was treated with thiobenzamide without any base (entries 1 and 7 in Table 3), 2,5-diphenyl-1,3-thiazol-4-ol (13) was the only product

Synthesis of imidazo[1,2-a]pyridine-containing peptidomimetics by tandem of Groebke–Blackburn–Bienaymé and Ugi reactions

• Oleksandr V. Kolomiiets,
• Alexander V. Tsygankov,
• Maryna N. Kornet,
• Aleksander A. Brazhko,
• Vladimir I. Musatov and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2023, 19, 727–735, doi:10.3762/bjoc.19.53

• organism's microflora. Conclusion To summarize, the study involved the combination of two multicomponent reactions – Groebke–Blackburn–Bienaymé and Ugi-type – to produce substituted 6-chloroimidazo[1,2-a]pyridin-2-ylphenoxy acetamides and 1H-imidazo[1,2-b][1,2,4]triazol-5-yl-phenoxy acetamide in a flexible

From amines to (form)amides: a simple and successful mechanochemical approach

• Federico Casti,
• Rita Mocci and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 1210–1216, doi:10.3762/bjoc.18.126

• mechanochemical conditions are presented. The two methodologies exhibit complementary features as they enable the derivatization of aliphatic and aromatic amines. Keywords: acetamides; formamides; mechanochemistry; N-formylation; p-tosylimidazole; Introduction The preparation of N-formylated and N-acetylated

• ][50][51][52][53][54], no systematic report of N-formylation and N-acetylation by ball milling has been reported yet. Here, we describe two complementary procedures to prepare formamides and acetamides, applied to primary and secondary aromatic and aliphatic amines. The methodologies directly involve

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• potential targets for the versatile pyrazolo[1,2,3]triazine library presented herein. Conclusion In analogy to literature-known acid-induced conversions of triazene-benzyl acetamides to 3,4-dihydrobenzo[d][1,2,3]triazines, so far not described pyrazolo[3,4-d][1,2,3]-3H-triazines 5 were successfully

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• of carbamates, sulfonamides and acetamides 13 bearing an α,β-unsaturated ketone to synthesize a series of 2-substituted five- and six-membered heterocycles in good yields (up to 99%) and excellent enantioselectivity (92–97.5% ee) (Table 3). As in an earlier case [29], several acids were tested as co

Direct C(sp³)–H allylation of 2-alkylpyridines with Morita–Baylis–Hillman carbonates via a tandem nucleophilic substitution/aza-Cope rearrangement

• Siyu Wang,
• Lianyou Zheng,
• Shutao Wang,
• Shulin Ning,
• Zhuoqi Zhang and
• Jinbao Xiang

Beilstein J. Org. Chem. 2021, 17, 2505–2510, doi:10.3762/bjoc.17.167

• acetamides and acetates catalyzed synergistically by a metal acyclic iridium complex and a chiral Cu(I) complex [19]. Besides transition-metal-catalyzed allylic substitution reactions, Lewis-base-catalyzed allylic functionalizations using Morita−Baylis−Hillman (MBH) adducts as electrophilic allylic

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• sufficient. The reaction tolerated (hetero)aryl and aliphatic tosyl hydrazones as radical acceptors and a variety of olefins with different electronic natures as nucleophilic partners (i.e., vinyl ethers, sulfides, and acetamides). One example of the synthesis of a quaternary center was reported by the

Synthesis of multiply fluorinated N-acetyl-D-glucosamine and D-galactosamine analogs via the corresponding deoxyfluorinated glucosazide and galactosazide phenyl thioglycosides

• Vojtěch Hamala,
• Lucie Červenková Šťastná,
• Martin Kurfiřt,
• Petra Cuřínová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2021, 17, 1086–1095, doi:10.3762/bjoc.17.85

• thioacetic acid [54][55]. Hence, the hemiacetals were reacted with thioacetic acid in pyridine to give acetamides 49–58 (Scheme 5) and the target trifluoro analogs 59 and 60. Reversing the order of hemiacetal and acetamide formation was not an option because NBS-promoted hydrolysis of 2-acetamido

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• to a series of pyrrolo[2,3-d]pyrimidine-2,4-diones acetamides 90 under microwave irradiation (Scheme 32). An interesting observation by the authors surfaced that the conventional approach to the malononitrile protocol delivered comparable yields in longer reaction time (5–8 h). A gram-scale attempt

α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams

• Mikhail K. Klychnikov,
• Radek Pohl,
• Ivana Císařová and
• Ullrich Jahn

Beilstein J. Org. Chem. 2021, 17, 688–704, doi:10.3762/bjoc.17.58

• simplified by further useful reaction steps. Results Tandem nucleophilic substitution/Brook rearrangement/radical α-oxygenation reactions The N-allylic α-(trimethylsilyl)acetamides 8a–m were efficiently prepared by a two-step sequence. First, N-allyl acetamides 11a–m were synthesized by N-acetylation of the

One-pot synthesis of substituted pyrrolo[3,4-b]pyridine-4,5-diones based on the reaction of N-(1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-2-oxo-2-arylethyl)acetamide with amines

• Valeriya G. Melekhina,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Vitaly S. Mityanov,
• Artem N. Fakhrutdinov,
• Arkady A. Dudinov,
• Vasily A. Migulin,
• Yulia V. Nelyubina,
• Elizaveta K. Melnikova and
• Michail M. Krayushkin

Beilstein J. Org. Chem. 2019, 15, 2840–2846, doi:10.3762/bjoc.15.277

• Federation Lomonosov Moscow State University, Moscow 119991, Russian Federation 10.3762/bjoc.15.277 Abstract The condensation of primary amines with N-(1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-2-oxo-2-arylethyl)acetamides was explored. Thus, a previously unknown recyclization of the starting material was

• strongly desirable. In this article, we describe a convenient synthetic method for the preparation of 6-alkyl-2-methyl-7-aryl-6,7-dihydro-1H-pyrrolo[3,4-b]pyridine-4,5-diones 1. Therein, the condensation of N-(1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-2-oxo-2-arylethyl)acetamides 2 with a diverse range of

• amines 3 did not only furnish the desired scaffolds in satisfactory yields but also allowed to use a variety of readily available substituted substrates (Scheme 1). Results and Discussion The published synthesis of acetamides 2 includes a one-pot three-component reaction of 4-hydroxy-6-methyl-2H-pyran-2

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Switchable selectivity in Pd-catalyzed [3 + 2] annulations of γ-oxy-2-cycloalkenones with 3-oxoglutarates: C–C/C–C vs C–C/O–C bond formation

• Yang Liu,
• Julie Oble and
• Giovanni Poli

Beilstein J. Org. Chem. 2019, 15, 1107–1115, doi:10.3762/bjoc.15.107

• , resonance-stabilized acetamides and cyclic α,β-unsaturated-γ-oxicarbonyl derivatives are used as bis-nucleophile and bis-electrophile partners, respectively. This process involves an intermolecular Pd(0)-catalyzed C-allylation (Tsuji–Trost reaction)/intramolecular nitrogen 1,4-addition sequence (Scheme 1

Synthetic and semi-synthetic approaches to unprotected N-glycan oxazolines

• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 416–429, doi:10.3762/bjoc.14.30

• donor 2, removed the 4,6-benzylidene, and then regioselectively glycosylated the free primary OH at position 6 with 2,6-branched trisaccharide trichloroacetimidate donor 3. Following conversion of the Troc groups into acetamides and reduction and acetylation of the azide, all of the acetates were

Syn-selective silicon Mukaiyama-type aldol reactions of (pentafluoro-λ⁶-sulfanyl)acetic acid esters with aldehydes

• Anna-Lena Dreier,
• Andrej V. Matsnev,
• Joseph S. Thrasher and
• Günter Haufe

Beilstein J. Org. Chem. 2018, 14, 373–380, doi:10.3762/bjoc.14.25

• -substituted acetamides into aldol additions with the intension of applying amides in Evans-type substrate directed asymmetric C–C-bond forming reactions. Therefore, 2-(pentafluoro-λ6-sulfanyl)acetic morpholide (8) was prepared by reaction of SF5-CH2C(O)Cl (7) [36][37] with morpholine (Scheme 5). According to

• conditions and application of enantiopure Lewis acids or SF5-substituted acetamides bearing a chiral auxiliary will result in asymmetric aldol addition reactions in the future. Conclusion From octyl SF5-acetate and TMSOTf/Et3N, a (Z)-enolate (ketene silylacetal) was preferentially formed as has already been

Syntheses of 3,4- and 1,4-dihydroquinazolines from 2-aminobenzylamine

• Jimena E. Díaz,
• Silvia Ranieri,
• Nadia Gruber and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2017, 13, 1470–1477, doi:10.3762/bjoc.13.145

• depicted in Table 3. Due to the different reactivity of each substrate, irradiation times and temperatures were individually adjusted. For the synthesis of compounds 1 the reaction conditions mainly depended on the steric and electronic features of the amido group present in the substrates. Acetamides and

• in precursors 5. The cyclodehydration of acetamides 5a–c proceeded under mild reaction conditions (Table 4, entries 1–3), while acetamide 5d required a higher temperature probably due to the steric hindrance produced by the N-isopropyl moiety (Table 4, entry 4). A higher temperature and a longer

TBHP-mediated highly efficient dehydrogenative cross-oxidative coupling of methylarenes with acetanilides

• Cui Chen,
• Weibing Liu and
• Peng Zhou

Beilstein J. Org. Chem. 2016, 12, 2250–2255, doi:10.3762/bjoc.12.217

• next investigated the reactions of p-xylene with N-phenylacetamide, N-p-tolylacetamide, N-(4-methoxyphenyl)acetamide, N-(2-chlorophenyl)acetamide and N-(3-chlorophenyl)acetamide under the standard conditions. Gratifyingly, all the tested acetamides reacted with p-xylene successfully, offering the

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• method for the synthesis of oxindoles and 3-oxotetrahydroisoquinolines 47 via intramolecular cyclization under C–C-bond formation was reported by Atobe, Fuchigami et al. (Scheme 18) [63]. The protocol is based on the anodic oxidation of α-(phenylthio)acetamides 46 in the presence of Et3N∙3HF. The latter

• ). Electrosynthesis of 39 as part of the total synthesis of alkaloids 40 and 41. Wacker-type cyclization of alkenyl phenols 42. Cathodic synthesis of indol derivatives. Fluoride mediated anodic cyclization of α-(phenylthio)acetamides. Synthesis of 2-substituted benzoxazoles from Schiff bases. Synthesis of euglobal

A simple copper-catalyzed two-step one-pot synthesis of indolo[1,2-a]quinazoline

• Chunpu Li,
• Lei Zhang,
• Shuangjie Shu and
• Hong Liu

Beilstein J. Org. Chem. 2014, 10, 2441–2447, doi:10.3762/bjoc.10.254

• ]quinazoline derivatives. (3) This protocol is performed as a two-step reaction in one pot. Results and Discussion Substituted N-(2-iodophenyl)acetamides 1 were synthesized from substituted 2-iodoaniline by acetylation [31][32]. Substituted o-iodobenzaldehydes 3 were prepared from 2-iodobenzoic acid

• -iodophenyl)acetamides with malononitriles and substituted o-iodobenzaldehydes was investigated. As summarized in Table 2, the desired products 4a–4q were obtained in moderate to good yields (34–72%) by treatment of various substituted N-(2-iodophenyl)acetamides 1a–1k with active methylene compounds 2a–2c and

• product (Table 2, entry 3). This result may be attributed to its low stability during the reaction. In comparison, electron-withdrawing p-trifluoromethyl and ester-substituted N-(2-iodophenyl)acetamides led to decreased yields of the desired compounds (Table 2, entries 4 and 5). Various halogens (F, Cl

Synthesis and immunological evaluation of protein conjugates of Neisseria meningitidis X capsular polysaccharide fragments

• Laura Morelli,
• Damiano Cancogni,
• Marta Tontini,
• Alberto Nilo,
• Sara Filippini,
• Paolo Costantino,
• Maria Rosaria Romano,
• Francesco Berti,
• Roberto Adamo and
• Luigi Lay

Beilstein J. Org. Chem. 2014, 10, 2367–2376, doi:10.3762/bjoc.10.247

• experienced a dramatic drop of the overall yield during the conversion of the azido groups in acetamides on protected glycosyl phosphosaccharide intermediates [25]. We therefore sought to design a different strategy based on GlcNAc instead of azido glucose building blocks, where the azide reduction is rather

• ). On the other hand, the same reaction carried out on protected glycosyl phosphosaccharides afforded the corresponding acetamides in 25–35% yield [25]. Interestingly, when compound 5 was subjected to 1-O-desilylation with tetrabutylammonium fluoride in THF at –40 °C, we obtained exclusively the α