Automated glycan assembly of a S. pneumoniae serotype 3 CPS antigen

• Markus W. Weishaupt,
• Stefan Matthies,
• Mattan Hurevich,
• Claney L. Pereira,
• Heung Sik Hahm and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2016, 12, 1440–1446, doi:10.3762/bjoc.12.139

• maintained for 30 min. The temporary Fmoc protecting group was cleaved with triethylamine in DMF (N,N-dimethylformamide; 10% v/v). The Lev protecting group was removed using hydrazine monohydrate in pyridine/acetic acid (3:2 v/v). The crude oligosaccharide products were cleaved from the solid support by

• -protected 3. The use of the buffered hydrazine solution for the cleavage of Lev TPGs was expected to prevent any undesired benzoyl ester cleavage. The trisaccharide synthesis was repeated using the same glycosylation conditions as in the previous synthesis (Scheme 2). After each glycosylation step, the pH

• tetrasaccharide addition sequence, resulting from benzoyl ester cleavage and a double glycosylation in the last step (see Supporting Information File 1). This result was not expected as the buffered hydrazine deprotection protocol had never favored the formation of side products in our hands. However, this

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

• phosphonates via ring opening through an intramolecular nucleophilic attack at the 2-position of the pyrone. Thus, the three-component reaction of 75 with hydrazine derivatives 76 or hydroxylamine 79 in the presence of diethyl phosphonate led to pyrazolylphosphonate 78 and oxazolylphosphonate 81, respectively

• -aryl-3-oxoisoindolin-1-yl)phosphonates. FeCl3 and PdCl2 co-catalyzed three-component reaction of 2-alkynylbenzaldehydes, anilines, and diethyl phosphonate. Three-component reaction of 6-methyl-3-formylchromone (75) with hydrazine derivatives or hydroxylamine in the presence of diethyl phosphonate

Unusual traits of cis and trans-2,3-dibromo-1,1-dimethylindane on the way from 1,1-dimethylindene to 2-bromo-, 3-bromo-, and 2,3-dibromo-1,1-dimethylindene

• Rudolf Knorr,
• David S. Stephenson,
• Ernst Lattke,
• Petra Böhrer and
• Jakob Ruhdorfer

Beilstein J. Org. Chem. 2016, 12, 1178–1184, doi:10.3762/bjoc.12.113

• -phenylbutan-2-ol, N-(1,1-dimethylindan-3-ylidene)hydrazine, and N,N´-bis(1,1-dimethylindan-3-ylidene)hydrazine. Acknowledgements This article is dedicated to Professor Manfred Heuschmann on the occasion of his retirement. Technical support of this research by the Organic Chemistry Division of the Department

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• azido β-CD was obtained by a Staudinger reaction or in the presence of hydrazine. A new generation of organophosphate scavengers has been obtained by Le Provost et al. [25] in which β-CD was regioselectively monosubstituted at O-2 using a bromomethyl pyridine derivative under US irradiation to avoid

• (GO) by MW irradiation (450 W) at different temperatures ranging from 50 to 100 °C for 10, 30, 60 and 90 min. After reduction with hydrazine hydrate, this HP-β-CD-RGO modified glassy carbon electrode showed good results in supramolecular recognition a set of six different phenolic organic pollutants

Hydroquinone–pyrrole dyads with varied linkers

• Hao Huang,
• Christoffer Karlsson,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 89–96, doi:10.3762/bjoc.12.10

• . achieved a total yield of 70% [11], however, their procedure relies on a Wolff–Kishner reduction of the corresponding acylpyrrole with hydrazine hydrate, making it impractical in countries where the use of hydrazine has been restricted by law [12]. As an alternative, the Suzuki–Miyaura reaction can be

A convenient four-component one-pot strategy toward the synthesis of pyrazolo[3,4-d]pyrimidines

• Mingxing Liu,
• Jiarong Li,
• Hongxin Chai,
• Kai Zhang,
• Deli Yang,
• Qi Zhang and
• Daxin Shi

Beilstein J. Org. Chem. 2015, 11, 2125–2131, doi:10.3762/bjoc.11.229

• results in hand, two possible reaction mechanisms were proposed and shown in Scheme 3. 5-Aminopyrazole-4-carbonitrile 6 was obtained from the reaction of hydrazine 1 and methylenemalononitrile 2 through nucleophilic addition, cyclization and aromatization. The nucleophilic attack of the amino group of 6

A new approach to ferrocene derived alkenes via copper-catalyzed olefination

• Vasily M. Muzalevskiy,
• Aleksei V. Shastin,
• Alexandra D. Demidovich,
• Namiq G. Shikhaliev,
• Abel M. Magerramov,
• Victor N. Khrustalev,
• Rustem D. Rakhimov,
• Sergey Z. Vatsadze and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

• , 28 Vavilov Street, Moscow 119991, Russia 10.3762/bjoc.11.223 Abstract A new approach to ferrocenyl haloalkenes and bis-alkenes was elaborated. The key procedure involves copper catalyzed olefination of N-unsubstituted hydrazones, obtained from ferrocene-containing carbonyl compounds and hydrazine

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• cation radical [31][32]. The doped film exhibited excellent stability and its absorption characteristics did not change despite treatment with hydrazine. However, de-doping was achieved with repetitive scanning of the polymer film over the range of −0.3–0 V vs Ag/AgCl for 2 hours [73]. After de-doping

The facile construction of the phthalazin-1(2H)-one scaffold via copper-mediated C–H(sp²)/C–H(sp) coupling under mild conditions

• Wei Zhu,
• Bao Wang,
• Shengbin Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 1624–1631, doi:10.3762/bjoc.11.177

• hydrazine hydrate and sodium hydroxide. Results and Discussion We initiated our investigation of the direct carbon–carbon coupling of N-(quinolin-8-yl)benzamide (1a) and phenylacetylene (2a). After extensive attempts, 3-benzylidene-2-(quinolin-8-yl)isoindolin-1-one (3a) was formed in 18% yield via the

• quinolin-8-amine was easily removed and recycled by treatment of 3a with hydrazine hydrate and NaOH in EtOH at 120 °C under microwave irradiation (Scheme 4). Both electron-rich and electron-deficient 4-benzylphthalazin-1(2H)-one derivatives were obtained in good yields (4b, 4k). The halo-substituted phenyl

• phthalazin-1(2H)-one scaffold by treatment with hydrazine hydrate and sodium hydroxide. As the phthalazin-1(2H)-one scaffold is identified as a privilege moiety and bioactive nucleus in pharmaceuticals, this modified procedure will be of importance to medicinal chemists. Experimental General procedure for

The enantioselective synthesis of (S)-(+)-mianserin and (S)-(+)-epinastine

• Piotr Roszkowski,
• Jan. K. Maurin and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2015, 11, 1509–1513, doi:10.3762/bjoc.11.164

• reacting amine 7 and ethyl chloro(oxo)acetate in dichloromethane in the presence of triethylamine. The removing of the phthaloyl protecting group from 8 using hydrazine gave an intermediate with a free amino group which is cyclised in situ to dioxopiperazine 9 in 90% yield. In the next step

• (S)-(+)-7 with hydrazine led to derivative 13 with deprotected amine function. Subsequent condensation with cyanogen bromide gave (S)-(+)-epinastine (2) in nearly quantitative yield. Conclusion In summary, we have presented a simple enantioselective synthesis of (S)-(+)-mianserin and (S

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• precipitation and clogging problems, thus a pressure chamber was developed [94] that would act as a pressure regulator allowing this step to be scaled up in flow in order to provide 114 on multigram scale (134 g/h). A Knorr pyrazole formation between 114 and commercially available hydrazine 115 had previously

Reactions of nitroxides 15. Cinnamates bearing a nitroxyl moiety synthesized using a Mizoroki–Heck cross-coupling reaction

• Jerzy Zakrzewski and
• Bogumiła Huras

Beilstein J. Org. Chem. 2015, 11, 1155–1162, doi:10.3762/bjoc.11.130

• , sometimes using of hydrazobenzene [51][52] or pentafluorophenyl hydrazine [35] as reducing agents have been reported, as well. The E geometry of 5a–i was confirmed by 1H NMR spectroscopy. The values of the coupling constants of the doublets visible in the 1H NMR spectra of 5a–i belonging to the double bond

Synthetic strategies for the fluorescent labeling of epichlorohydrin-branched cyclodextrin polymers

• Milo Malanga,
• Mihály Bálint,
• István Puskás,
• Kata Tuza,
• Tamás Sohajda,
• László Jicsinszky,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3007–3018, doi:10.3762/bjoc.10.319

• branched β-CD-polymer is a difficult task. 2) Reduction of the azido groups to amino moieties There are several and selective ways to perform the azido→amino conversion [22] and for compound 1 the hydrogenolytic method [23] based on hydrazine, catalyzed by Pd/C (Scheme 2) was selected. The reaction using

• hydrazine-Pd/C is fast and exhaustive (based on the evaluation of the IR spectra, Figure 3), but because of the laborious work-up (filtration, centrifugation, membrane filtration) and the partial inefficacy of the dialysis purification, this method needed further development. The overall progress of the

Synthesis of the pentasaccharide repeating unit of the O-antigen of E. coli O117:K98:H4

• Pintu Kumar Mandal

Beilstein J. Org. Chem. 2014, 10, 2724–2728, doi:10.3762/bjoc.10.287

• ),4.35 (d, J = 7.8 Hz, 1H, H-1A) and at δ 104.0 (C-1A), 101.2 (C-1D), 98.9 (C-1B), 98.3 (C-1C), 97.4 (C-1E) in the 1H and 13C NMR spectra, respectively]. The N-phthaloyl group was removed using hydrazine hydrate and the free amine thus formed was acetylated using acetic anhydride in pyridine [35]. Then

One-pot four-component reaction for convenient synthesis of functionalized 1-benzamidospiro[indoline-3,4'-pyridines]

• Chao Wang,
• Yan-Hong Jiang and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2014, 10, 2671–2676, doi:10.3762/bjoc.10.281

• generation of Huisgen’s 1,4-dipoles are aromatic heterocycles such as N-alkylimidazole, pyridine, quinoline, isoquinoline and primary aromatic amines. In recent years, other nitrogen-containing nucleophiles such as hydrazine and arylhydrazines are also used to generate Huisgen’s 1,4-dipoles in domino

• -3,4’-pyridine] derivatives can be synthesized by employing other nitrogen-containing nucleophiles such as hydrazine and imines in the similar four-component reactions. In fact, the four-component reaction of hydrazine, acetylenedicarboxylate, isatin and malononitrile for the formation of spiro

• triethylamine as the base catalyst were introduced into reaction system. The subsequent reaction proceeded very smoothly at room temperature to give the 1'-benzamidospiro[indoline-3,4’-pyridines] 1a–d in satisfactory yields (Table 1, entries 1–4). It is known that hydrazine reacts firstly with

Facile synthesis of 1H-imidazo[1,2-b]pyrazoles via a sequential one-pot synthetic approach

• András Demjén,
• Márió Gyuris,
• János Wölfling,
• László G. Puskás and
• Iván Kanizsai

Beilstein J. Org. Chem. 2014, 10, 2338–2344, doi:10.3762/bjoc.10.243

• [1,2-b]pyrazole library in sequential one-pot protocol utilizing four components such as hydrazine hydrate, ethoxymethylene substituted malononitrile or ethyl cyanoacetate derivatives, isocyanides and aldehydes. Results and Discussion In the initial stage, a model GBB-3CR was performed between 5

• envisage a sequential one-pot access to 1H-imidazo[1,2-b]pyrazole species through the in situ microwave-assisted formation of 1a followed by a GBB-3CR. A comparative study for the optimum synthesis of 6 revealed that the cyclocondensation of ethoxymethylene malononitrile (4a) with hydrazine (5) under

(CF₃CO)₂O/CF₃SO₃H-mediated synthesis of 1,3-diketones from carboxylic acids and aromatic ketones

• JungKeun Kim,
• Elvira Shokova,
• Victor Tafeenko and
• Vladimir Kovalev

Beilstein J. Org. Chem. 2014, 10, 2270–2278, doi:10.3762/bjoc.10.236

• following reaction with hydrazine hydrate gave the pyrazoles 6a–d in 62–76% yield. The products were identified by 1H and 13C NMR spectroscopy, microanalysis and by spectral comparison with the known compounds. The molecular structures of compounds 3с, 3u, 4a, 6b were confirmed by X-ray diffraction [26

• . Then TfOH (44 μL, 0.5 mmol) was added, and the reaction mixture was kept for 2 h. On completion of the reaction, the solvent was removed under reduced pressure. The crude 3a was dissolved in 5 mL ethanol and heated under reflux with hydrazine hydrate (0.1 mL, 2 mmol). After 2 h the solvent was

Derivatives of the triaminoguanidinium ion, 3. Multiple N-functionalization of the triaminoguanidinium ion with isocyanates and isothiocyanates

• Jan Szabo,
• Kerstin Karger,
• Nicolas Bucher and
• Gerhard Maas

Beilstein J. Org. Chem. 2014, 10, 2255–2262, doi:10.3762/bjoc.10.234

• coordination architectures in the solid state. TAG-Cl (1) was first prepared from carbon tetrachloride and hydrazine by R. Stollé in the year 1904 [7], but it was not until half a century later that some interest in its chemistry emerged. Derivatization reactions with aldehydes and ketones furnished tris

Syntheses of ¹⁵N-labeled pre-queuosine nucleobase derivatives

• Jasmin Levic and
• Ronald Micura

Beilstein J. Org. Chem. 2014, 10, 1914–1918, doi:10.3762/bjoc.10.199

• with hydrazine hydrate. The previously published route [11] recommended N-Boc functionalization of the preQ1 base in the crude reaction mixture to enable flash chromatography on SiO2 followed by cleavage of the auxiliary function, however, although robust in handling, the yields were rather modest. We

• = 88.96 Hz, 2H, 15NH2-C2), 6.36 (s, 1H, H-C8), 7.85–7.87 (m, 4H, arom H), 10.42 (d, J = 89.21 Hz, 1H, 15N1-H), 10.81 (s, 1H, NH) ppm. Trifluoroacetate salt of [15N1,15N3,H215N(C2)]-7-(aminomethyl)-7-deazaguanine (1). Compound 8 (70 mg, 0.22 mmol) was added to a solution containing hydrazine hydrate (111

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• irradiation-assisted condensation of sugar hydrazine 115, 4-chlorobenzothioamide and an aromatic aldehyde in the presence of (diacetoxyiodo)benzene (Scheme 48) [125]. The conversion of 4-chlorobenzothioamide to 4-(chlorophenyl)isothiocyanate intermediate by (diacetoxyiodo)benzene was suggested to initiate the

Chemistry of polyhalogenated nitrobutadienes, 14: Efficient synthesis of functionalized (Z)-2-allylidenethiazolidin-4-ones

• Viktor A. Zapol’skii,
• Jan C. Namyslo,
• Mimoza Gjikaj and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2014, 10, 1638–1644, doi:10.3762/bjoc.10.170

• cyclization step, a series of (Z)-2-allylidenethiazolidin-4-ones was obtained in yields up to 81%. Some subsequent reactions have been examined too, such as the formation of perfunctionalized 1H-pyrazoles upon treatment with hydrazine. Thiazolidinones are as well known for their physiological activities as

• -inhibiting and antialgal properties [49], show anticancer activity [50][51], and are inhibitors of bacterial enzyme synthetase MurD with E. coli [52]. Additional treatment of thiazolidin-4-one 8 with a fivefold excess of hydrazine hydrate resulted in the formation of a 1H-pyrazole: A total of two hydrazine

• furnished the corresponding 1H-pyrazole 28 in 52% yield (Scheme 5). A plausible multistep mechanism of this conversion is shown in Scheme 6: Initially, a first molecule of the strong nucleophile hydrazine is assumed to substitute the single C–Cl group within the trichlorovinyl subunit of 8 to give the

Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

• Anastasia S. Kostyuchenko,
• Vyacheslav L.Yurpalov,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2014, 10, 1596–1602, doi:10.3762/bjoc.10.165

• lower electrophilicity and a bigger steric hindrance at the carbethoxy group. The hydrazide derivative 10 was obtained by refluxing 3 with hydrazine monohydrate in alcohol. Hydrazinolysis of 7 under these conditions runs slow and leads to a mixture of products (Scheme 3). Diacylhydrazine 11 was prepared

• by the reaction of carboxylic acid 8 and hydrazide 10 in the presence of dicyclohexylcarbodiimide (DCC) in 78% yield. Compound 12 was obtained in 60% yield by reacting hydrazine monohydrate and the carboxylic acid chloride which was prepared in situ from 9 with oxalyl chloride (Scheme 4). It is known

Multivalent scaffolds induce galectin-3 aggregation into nanoparticles

• Candace K. Goodman,
• Mark L. Wolfenden,
• Pratima Nangia-Makker,
• Anna K. Michel,
• Avraham Raz and
• Mary J. Cloninger

Beilstein J. Org. Chem. 2014, 10, 1570–1577, doi:10.3762/bjoc.10.162

• -oxapentyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl-[1→4]-2,3,6-tri-O-acetyl-β-D-glucopyranoside (1) 2,3,4,6-Tetra-O-acetyl-β-D-galactopyranose-[1→4]-1,2,3,6-tetra-O-acetyl-β-D-glucopyranose (4.4 g, 6.4 mmol) was dissolved in dry DMF (20 mL). Hydrazine acetate (0.77 g, 8.4 mmol) was added and the reaction

Glycosystems in nanotechnology: Gold glyconanoparticles as carrier for anti-HIV prodrugs

• Fabrizio Chiodo,
• Marco Marradi,
• Javier Calvo,
• Eloisa Yuste and
• Soledad Penadés

Beilstein J. Org. Chem. 2014, 10, 1339–1346, doi:10.3762/bjoc.10.136

• thioacetate [31], was reacted with ABC and 3TC in DMF in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and 4-dimethylaminopyridine (DMAP) to obtain the ester derivative in ~75% yield. After purification, the protecting group of the thiol was removed with hydrazine acetate to give the

Automated solid-phase peptide synthesis to obtain therapeutic peptides

• Veronika Mäde,
• Sylvia Els-Heindl and
• Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

• specific conditions as, e.g., hydrazine (Dde (1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)-3-ethyl) group [40]), very low concentrated acids (Mmt (monomethoxytrityl) group [41]), palladium-catalyzed cleaving conditions (Alloc (allyloxycarbonyl) group [42]) or UV light (Nvoc (6-nitroveratryloxycarbonyl

• -dimethyl-2,6-dioxocyclohex-1-ylidene)-3-methylbutyl) [105] and Dde [40] (deprotection with 2% hydrazine in DMF (N,N-dimethylformamide)) or the Alloc group [42] (cleavage with catalytically amounts of Pd(PPh)3 under inert conditions) are recommended. A selective removal of the side-chain protecting group