Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

• Cristina Morar,
• Pedro Lameiras,
• Attila Bende,
• Gabriel Katona,
• Emese Gál and
• Mircea Darabantu

Beilstein J. Org. Chem. 2018, 14, 1704–1722, doi:10.3762/bjoc.14.145

• (Figure 1). In the synthesis of 7a, unexpectedly difficult conditions for this type of reaction were, once again, required. Similar amidations run in triplicate using instead the acid chlorides of C1 and C3 provided negative results. Thus, although the protocol for the conversion of these (4-aminophenoxy

• )alkanoic acid-based tripodal melamines into the corresponding tri acid chlorides (not depicted in Scheme 4) followed typical procedures (in refluxing thionyl chloride with SO2 and HCl generation), a long reaction time (up to 24 h, as determined by HRMS monitoring) was mandatory for this transformation to

• go to completion. The crude isolated products exhibited very low solubility in solvents usually recommended for standard N-acylations (acetone, THF, 1,4-dioxane, pyridine, etc.). Treatment of these acid chlorides with G-1 dendron D-N

  NH (3 equiv) under various conditions (microwave-assisted organic

Derivatives of the triaminoguanidinium ion, 5. Acylation of triaminoguanidines leading to symmetrical tris(acylamino)guanidines and mesoionic 1,2,4-triazolium-3-aminides

• Jan Szabo,
• Julian Greiner and
• Gerhard Maas

Beilstein J. Org. Chem. 2017, 13, 579–588, doi:10.3762/bjoc.13.57

• Jan Szabo Julian Greiner Gerhard Maas Institute of Organic Chemistry I, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany 10.3762/bjoc.13.57 Abstract Depending on the reaction conditions, N,N’,N’’-tris(benzylamino)guanidinium salts can react with carboxylic acid chlorides to form

• been addressed only rarely, reactions with acid chlorides appear to be unknown. We have recently reported on the threefold carbamoylation of N,N’,N’’-tris(benzylamino)guanidinium salts with aryl isocyanates [3]. Concerning the reaction with carboxylic acids, it is known that TAG-Cl and formic acid on

• metals [20]. In subsequent studies, Busch and co-workers found that a variety of 5-substituted 1,2,4-triazolium-3-aminides III (Scheme 1) can be prepared either in one step from triphenylaminoguanidine and acid chlorides at elevated temperatures or in two steps using an aldehyde and subsequent oxidation

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• .13.48 Abstract This comprehensive review describes methods for the preparation of 1-indanones published in original and patent literature from 1926 to 2017. More than 100 synthetic methods utilizing carboxylic acids, esters, diesters, acid chlorides, ketones, alkynes, alcohols etc. as starting materials

• new method for the synthesis of pure indatraline ((−)-29) in a sequence of reactions starting from carboxylic acid 27 (Scheme 10). 1.1.2 From acid chlorides: The first synthesis of unsubstituted 1-indanone (2), obtained from the reaction of phenylpropionic acid chloride with aluminum chloride in

• benzene (90% yield), has been published in 1927 [24]. In the same year, Mayer and Müller have described a cyclization of unsaturated ketones with acid chlorides leading to the formation of 1-indanones [25]. The use of other acidic catalysts, like ZnBr2 or Nafion®-H also led to the formation of 1-indanones

Synthesis and optical properties of new 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles

• Anastasia S. Kostyuchenko,
• Tatyana Yu. Zheleznova,
• Anton J. Stasyuk,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2017, 13, 313–322, doi:10.3762/bjoc.13.34

• synthesis of 14d–g. These intermediates were synthesized by the reaction of the acid chlorides with hydrazine dihydrochloride in the presence of pyridine. The required acid chlorides were prepared in situ through the reaction of the corresponding carboxylic acids 12b–g with oxalyl chloride. The yields of

A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues

• Arno Verlee,
• Thomas Heugebaert,
• Tom van der Meer,
• Pavel I. Kerchev,
• Frank Van Breusegem and
• Christian V. Stevens

Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33

• one single step. Furthermore, acid chlorides show a high reactivity [21] making m-(chlorosulfonyl)benzoyl chloride an ideal starting material as was shown by Yang et al. [18]. By transferring this reaction to a multistep flow set-up, we envisioned an improved chemoselectivity. This phenomenon is not

A novel method for heterocyclic amide–thioamide transformations

• Walid Fathalla,
• Ibrahim A. I. Ali and
• Pavel Pazdera

Beilstein J. Org. Chem. 2017, 13, 174–181, doi:10.3762/bjoc.13.20

• -one (A1) [18] was prepared by Niementowski reaction by fusion of anthranilic acid with formamide at 120 °C for 5 h. A number of quinazoline derivatives A2–A6 [19][20][21] were prepared via sequential steps starting from easily available carboxylic acid chlorides. The acid chlorides reacted with

Catalytic Wittig and aza-Wittig reactions

• Zhiqi Lao and
• Patrick H. Toy

Beilstein J. Org. Chem. 2016, 12, 2577–2587, doi:10.3762/bjoc.12.253

• materials (Scheme 19) [37]. For example, reactions of carboxylic acids 71 with acid chlorides 72 to generate the corresponding carboxylic acid anhydride in situ afforded 4H-benzo[d][1,3]-oxazin-4-ones 73. In these reactions, 1 was used as the catalyst for the aza-Wittig reaction and copper triflate was used

• as the catalyst for phosphine oxide reduction. Using similar conditions the corresponding reactions of carboxylic acids 74 with aromatic acid chlorides 72 produced 4-benzylidene-2-aryloxazol-5(4H)-ones 75. Lastly, the research group of Piet Herdewijn extended this general concept and reported

A direct method for the N-tetraalkylation of azamacrocycles

• Andrew J. Counsell,
• Angus T. Jones,
• Matthew H. Todd and
• Peter J. Rutledge

Beilstein J. Org. Chem. 2016, 12, 2457–2461, doi:10.3762/bjoc.12.239

• quaternary amine species. A number of alternative approaches have been investigated, with differing degrees of success. For example Alcock et al. deployed a two-step route using acid chlorides to first form an intermediate amide, and then reduced this with borane in THF to the tertiary amine; yields were

Elongated and substituted triazine-based tricarboxylic acid linkers for MOFs

• Arne Klinkebiel,
• Ole Beyer,
• Barbara Malawko and
• Ulrich Lüning

Beilstein J. Org. Chem. 2016, 12, 2267–2273, doi:10.3762/bjoc.12.219

• (see below). The syntheses of larger linkers 2 therefore need: (i) substituted 4-bromobenzoic acid chlorides 5, 4-bromobenzonitrile (6) and the methoxycarbonyl-substituted phenylboronic acid 15 (n = 1) or pinacol biphenylboronate 18 (n = 2). Syntheses Four functional groups were chosen as additional

• substituents in the extended triazine linkers 2: nitro, methoxy, amino and hydroxy groups. An amino group can be obtained from a nitro group by reduction, and a hydroxy group by cleavage of a methoxy group. Therefore, it was sufficient to synthesize the nitro and methoxy-substituted acid chlorides 5 for the

Tunable microwave-assisted method for the solvent-free and catalyst-free peracetylation of natural products

• Manuela Oliverio,
• Paola Costanzo,
• Monica Nardi,
• Carla Calandruccio,
• Raffaele Salerno and
• Antonio Procopio

Beilstein J. Org. Chem. 2016, 12, 2222–2233, doi:10.3762/bjoc.12.214

• ]. Classically peracetylation reactions have been performed by treatment of alcohols and phenols with acid anhydrides or acid chlorides in the presence of bases [12]. Recently, the urgency to find more environmental benign methods for standard transformations, led to the optimization of methods employing

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

• Mohammad Haji

Beilstein J. Org. Chem. 2016, 12, 1269–1301, doi:10.3762/bjoc.12.121

• the three-component reaction of 4-chlorobenzaldehyde (238), aminomethylphosphonate 239 and ynones 240 in 57% yield (Scheme 49). 7 Reissert-type multicomponent reactions The traditional Reissert reaction is a one-pot treatment of quinoline (242) with acid chlorides 243 and KCN to afford Reissert

Synthesis of highly functionalized 2,2'-bipyridines by cyclocondensation of β-ketoenamides – scope and limitations

• Paul Hommes and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2016, 12, 1170–1177, doi:10.3762/bjoc.12.112

• in 42% yield. The corresponding β-ketoenamides containing pyridine moieties at the acylated nitrogen were prepared by standard methods with the respective acid chlorides that furnished compounds 3c and 3d in good yields. For the synthesis of compound 3e it was advantageous to employ the benzotriazole

Investigation on the reactivity of α-azidochalcones with carboxylic acids: Formation of α-amido-1,3-diketones and highly substituted 2-(trifluoromethyl)oxazoles

• Kandasamy Rajaguru,
• Arumugam Mariappan,
• Rajendran Suresh,
• Periasamy Manivannan and
• Shanmugam Muthusubramanian

Beilstein J. Org. Chem. 2015, 11, 2021–2028, doi:10.3762/bjoc.11.219

• opening of 6 (Scheme 2). Having established the formation of 3 from azidochalcones with carboxylic acids under microwave conditions, the efficiency of this conversion was checked by replacing the carboxylic acids with equivalent systems such as acid chlorides, thioacetic acids, anhydrides, esters and

Synthesis of multivalent carbohydrate mimetics with aminopolyol end groups and their evaluation as L-selectin inhibitors

• Joana Salta,
• Jens Dernedde and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2015, 11, 638–646, doi:10.3762/bjoc.11.72

• route [24][27][28], whereas serinol (2) is commercially available. As a first approach to construct amide derivatives we envisioned the Schotten–Baumann acylation using acid chlorides. For this purpose a protection of the hydroxy groups of aminopyran 1 with the tert-butyldimethylsilyl (TBS) group was

• In this article we disclose the preparation of divalent and trivalent carbohydrate mimetics with end groups derived from aminopyran 1 and serinol (2). The units were connected by amide bonds that were either formed by Schotten–Baumann reaction using the corresponding acid chlorides or by a coupling

Novel biphenyl-substituted 1,2,4-oxadiazole ferroelectric liquid crystals: synthesis and characterization

• Mahabaleshwara Subrao,
• Dakshina Murthy Potukuchi,
• Girish Sharada Ramachandra,
• Poornima Bhagavath,
• Sangeetha G. Bhat and
• Srinivasulu Maddasani

Beilstein J. Org. Chem. 2015, 11, 233–241, doi:10.3762/bjoc.11.26

• The synthesis of 1,2,4-oxadiazoles involves [30] a single stage dehydration of O-acylated amidoximes via a reaction between amidoximes and derivatives of carbonyl compounds (esters, amides, acids, acid chlorides, aldehydes, etc.). Otherwise, the reaction is based on the 1,3-dipolar cycloaddition of N

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• transition state is eliminated by oxygen–phosphorus lone pair–lone pair repulsion. Conclusion High-yield syntheses have been developed for some novel phosphorus synthons, including the acyl and benzoyldiamidites via the surprising condensation of phosphonodiamidite 4 and the two acid chlorides with

• –C1–O 120.23(8), P–C1–C2 119.78(8), C2–C1–O 119.82(9). Synthesis of a dinucleoside acylphosphonate (3b) and a formate diester (1a). Reaction of an H-phosphonodiamidite with acid chlorides. Synthesis of dinucleosides. Calculated phosphine, acylphosphine, phosphite, and acylphosphonite inversion

Triazol-substituted titanocenes by strain-driven 1,3-dipolar cycloadditions

• Andreas Gansäuer,
• Andreas Okkel,
• Lukas Schwach,
• Laura Wagner,
• Anja Selig and
• Aram Prokop

Beilstein J. Org. Chem. 2014, 10, 1630–1637, doi:10.3762/bjoc.10.169

• building blocks [23][24][25]. From these compounds the corresponding acid chlorides can be prepared by addition of SOCl2. The acid chloride group is more electrophilic than the [TiCl2] fragment and therefore many titanocenes containing ligands with pending amide, ester, and ketone groups can be prepared

• allow to study the effect of substitution on the activity of the complexes. The ether tether in B serves as a model for PEG. The titanocene carboxylates 1–3 were transformed into the corresponding acid chlorides and then reacted with amino azides A–D in the presence of NaH without purification of the

• acid chlorides. Typical results are summarized in Table 1. Gratifyingly, the acylation reactions proceed without problems and the azide-functionalized titanocenes can generally be obtained in good yields after 16 h. The somewhat lower yields obtained with carboxylate 3 are probably due to an increased

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

• by reacting thiobenzoic acid, isocyanoacetate, two aliphatic aldehydes (iPr, t-Bu) and benzylamines/ammonia in either methanol (for benzylamines) or trifluoroethanol (for ammonia) [108]. Then, subsequent hydrolysis of the methylester followed by activation via acid chlorides or triflates gave the 5

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• , N-benzylimines and acid chlorides. The reaction was catalyzed by a Au(III)–salen complex 22 and occurred in acetonitrile at 170 °C under dielectric heating (Scheme 15). On the basis of the results of some smart kinetic experiments on ad-hoc synthetized plausible intermediates (III and V) in the

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

Flow microreactor synthesis in organo-fluorine chemistry

• Hideki Amii,
• Aiichiro Nagaki and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2013, 9, 2793–2802, doi:10.3762/bjoc.9.314

• –elimination mechanism is a fundamental reaction in organic synthesis. Acid fluorides are known to be more stable to hydrolysis than acid chlorides under acidic or neutral conditions; on the other hand, they react with nucleophiles vigorously under basic conditions. Amino acid fluorides serve as one of the

Expeditious, mechanochemical synthesis of BODIPY dyes

• Laramie P. Jameson and
• Sergei V. Dzyuba

Beilstein J. Org. Chem. 2013, 9, 786–790, doi:10.3762/bjoc.9.89

• better yields (albeit reaction times of several days are often encountered), the structural diversity of commercially available acid chlorides is limited, and they must be prepared from the corresponding acid. Furthermore, the sensitivity of acid chlorides to moisture imposes additional constrains

• ) and isolation of the dyes is performed by chromatography, with poor to moderate (10–50%) yields. In this light, a more expedient synthesis of the BODIPY dyes is desired. Toward this end, we reasoned that the condensation step between the 2-substituted pyrroles and aldehydes (or acid chlorides) should

• Information File 1, Table S1). Yet, the reaction times are drastically reduced from hours and several days (the latter holds true, for example, for dyes 4, 6, 7) to just 5 minutes. Furthermore, we examined whether acid chlorides would be suitable substrates for this procedure (Scheme 3). It appeared that the

Intramolecular carbolithiation of N-allyl-ynamides: an efficient entry to 1,4-dihydropyridines and pyridines – application to a formal synthesis of sarizotan

• Wafa Gati,
• Mohamed M. Rammah,
• Mohamed B. Rammah and
• Gwilherm Evano

Beilstein J. Org. Chem. 2012, 8, 2214–2222, doi:10.3762/bjoc.8.250

• isolated in modest yields (30–33%), even in the presence of additional HMPA, which might may constitute the major limitation of our process. Other attempts involving electrophiles such as acid chlorides and allyl bromide or transmetallation with zinc chloride and Negishi cross-coupling were unsuccessful

Chemical modification allows phallotoxins and amatoxins to be used as tools in cell biology

• Jan Anderl,
• Hartmut Echner and
• Heinz Faulstich

Beilstein J. Org. Chem. 2012, 8, 2072–2084, doi:10.3762/bjoc.8.233

• . After evaporation in vacuo at 60 °C, the aminophalloidin was purified on a Sephadex-LH20 column with methanol as eluant. Yield of aminophalloidin was 80%, purity 89% by HPLC. Fatty acid amides of phalloidin Aminophalloidin and the fatty acid chlorides were reacted as described for the synthesis of

Amines as key building blocks in Pd-assisted multicomponent processes

• Didier Bouyssi,
• Nuno Monteiro and
• Geneviève Balme

Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163

• precatalysts and ligands, the palladacycle 10 in combination with the di-tert-butyl-2-biphenylphosphine (11) furnished the best results in terms of reaction time and yield. A large variety of imines and acid chlorides can be used in this reaction, with only enolizable imines and those bearing bulky nitrogen

• pyrazoles in a consecutive fashion from terminal alkynes, acid chlorides, and hydrazine derivatives. Classical approaches to these valuable compounds are notably based on the cyclocondensation of hydrazine derivatives with 1,3-disubstituted three-carbon units, including α,β-unsaturated ketones, and

• particularly alkynones. In situ generation of the latter is an interesting means of overcoming the poor commercial availability of these compounds and also offers the flexibility needed for library production (Scheme 15). Thus various (hetero)aryl acid chlorides and terminal alkynes were heated in THF in the