3-Pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes, and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides, and ring contraction to cyanopyrroles and cyanoindoles

• Curt Wentrup,
• Nguyen Mong Lan,
• Adelheid Lukosch,
• Pawel Bednarek and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 743–753, doi:10.3762/bjoc.9.84

• dimethylpyrimidine-carbonitriles [38][39] by adaptation of the literature method [36][37]. 4,6-Dimethyl-2-(5-tetrazolyl)pyrimidine (24): From 3.0 g (22.5 mmol) of 4.6-dimethylpyrimidine-2-carbonitrile was obtained 2.8 g (71%); mp 209–210 °C (dec); 1H NMR (CDCl3) 12.0 (very broad), 7.37 (s, 1H), 2.50 (s, 6H); MS m/z

A new family of four-ring bent-core nematic liquid crystals with highly polar transverse and end groups

• Kalpana Upadhyaya,
• Venkatesh Gude,
• Golam Mohiuddin and
• Rao V. S. Nandiraju

Beilstein J. Org. Chem. 2013, 9, 26–35, doi:10.3762/bjoc.9.4

• designed from 3-substituted 2-chlorobenzoic acid and then coupled with 4'-hydroxy-[1,1'-biphenyl]-4-carbonitrile to achieve the target compound. The chloro substituent creates a strong transverse dipole moment, which may favour polar ordering. Commercially available 2-chloro-3-nitrobenzoic acid (2), is

• )amino)-2-chlorobenzoic acids 6a–6c. Coupling of these acids with 4’-hydroxy-[1,1'-biphenyl]-4-carbonitrile in the presence of N,N’-dicyclohexylcarbodiimide (DCC) and a catalytic amount of dimethylaminopyridine (DMAP) produced the desired products 4'-cyanobiphenyl-4-yl 2-chloro-3-[((2-hydroxy-4-n

• -carbonitrile (0.195 g, 1.0 mmol) and a catalytic amount of N,N'-dimethylaminopyridine (DMAP) dissolved in dry dichloromethane (DCM) (50 mL) in a round-bottom two-neck flask flushed with N2, arranged with a teflon-coated magnetic stirrer at room temperature. The reaction mixture was stirred for 48 h at room

On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

• Virginia Mazzanti,
• Martina Cacciarini,
• Søren L. Broman,
• Christian R. Parker,
• Magnus Schau-Magnussen,
• Andrew D. Bond and
• Mogens B. Nielsen

Beilstein J. Org. Chem. 2012, 8, 958–966, doi:10.3762/bjoc.8.108

• , 52.58; H, 2.41; N, 6.69. 3,7-Dibromo-2-phenylazulene-1-carbonitrile (14): To a solution of 4 excluded from light (154 mg, 0.46 mmol) (prepared as previously described [12]) in CH2Cl2 (4 mL) at −78 °C under a N2 atmosphere was slowly added a 0.78 M solution of Br2 (0.59 mL, 0.46 mmol) in CH2Cl2. After

• ; found, 385.9196. 3-Bromo-2-phenyl-7-(triisopropylsilylethynyl)azulene-1-carbonitrile (15): To a mixture of the azulene 14 (18 mg, 0.047 mmol), Pd(PPh3)2Cl2 (4 mg) and CuI (2 mg) in argon-degassed THF (4 mL) under an Ar atmosphere were added iPr2NH (40 μL, 0.283 mmol) and triisopropylsilylacetylene (30

• , CDCl3) δ 151.9, 143.7, 142.1, 139.4, 139.2, 138.0, 132.9, 130.3, 129.8, 128.8, 127.4, 124.1, 116.5, 108.9, 106.0, 97.6, 95.1, 18.9, 11.5 ppm; HRMS–ESI (m/z): [M + H]+ calcd for C28H31BrNSi, 488.1404; found, 488.1398. 3-Bromo-7-(2’,5’-dimethoxyphenyl)-2-phenylazulene-1-carbonitrile (17): To a solution of

Synthesis and mesomorphic properties of calamitic malonates and cyanoacetates tethered to 4-cyanobiphenyls

• Katharina C. Kress,
• Martin Kaller,
• Kirill V. Axenov,
• Stefan Tussetschläger and
• Sabine Laschat

Beilstein J. Org. Chem. 2012, 8, 371–378, doi:10.3762/bjoc.8.40

• ) and then methyl 3-chloro-3-oxopropionate (10) (114 mg, 0.84 mmol) were added over 10 min at 0 °C under a N2 atmosphere to a solution of 4'-((6-hydroxyhexyl)oxy)-[1,1'-biphenyl]-4-carbonitrile (9a) (500 mg, 1.69 mmol) in abs. CH2Cl2 (5 mL). The reaction mixture was stirred at 0 °C for 1 h, then for 2 h

• )-[1,1'-biphenyl]-4-carbonitrile (9b) (560 mg, 1.60 mmol), methyl 3-chloro-3-oxopropionate (10) (109 mg, 0.80 mmol) and pyridine (126 mg, 1.60 mmol) in abs. CH2Cl2 (5 mL). The crude product was purified by column chromatography on silica gel (gradient: hexanes/EtOAc, 20:1, then 15:1) to give 11b as a

• C27H33NO5: C, 71.82; H, 7.37; N, 3.10; found: C, 71.66; H, 7.34; N, 3.03; Rf 0.76 (hexanes/EtOAc 2:1). 6-[(4'-cyano-[1,1'-biphenyl]-4-yl)oxy]hexyl 2-cyanoacetate (13a) To a solution of 4'-((6-hydroxyhexyl)oxy)-[1,1'-biphenyl]-4-carbonitrile (9a) (100 mg, 338 μmol) in abs. CH2Cl2 (2.5 mL) were added

Regioselectivity in the multicomponent reaction of 5-aminopyrazoles, cyclic 1,3-diketones and dimethylformamide dimethylacetal under controlled microwave heating

• Kamal Usef Sadek,
• Ramadan Ahmed Mekheimer,
• Tahany Mahmoud Mohamed,
• Moustafa Sherief Moustafa and
• Mohamed Hilmy Elnagdi

Beilstein J. Org. Chem. 2012, 8, 18–24, doi:10.3762/bjoc.8.3

• triethylamine as base produces the more thermodynamically stable dihydropyridine (Hantzsch-type product). In addition, the nature of the catalyst plays an important role [20]. A one-pot three component reaction of 5-amino-1H-pyrazole-4-carbonitrile, dimedone and triethylorthoesters in toluene under reflux was

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities

• Hany M. Mohamed,
• Ashraf H. F. Abd EL-Wahab,
• Ahmed M. EL-Agrody,
• Ahmed H. Bedair,
• Fathy A. Eid,
• Mostafa M. Khafagy and
• Kamal A. Abd-EL-Rehem

Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199

• ethyl 6,8-diiodocoumarin-3-carboxylate (1) with ethyl cyanoacetate/NH4OAc gave ethyl 2-(3-carbamoyl-6,8-diiodocoumarin-4-yl)-2-cyanoacetate (12) and 2-amino-4-hydroxy-7,9-diiodocoumarino[3,4-c]pyridine-1-carbonitrile (13), and treatment with acetone in the presence of NH4OAc or methylamine gave the

• -6,8-diiodocoumarin-4-yl)-2-cyanoacetate (12) and the soluble reaction product was identified as 2-amino-4-hydroxy-7,9-diiodocoumarino[3,4-c]pyridine-1-carbonitrile (13), which probably formed as a result of amide formation, dehydration and intramolecular cyclization (Scheme 4). The structures of

• ), 264 (4.0), 236 (35.0). 2-Amino-4-hydroxy-7,9-diiodocoumarino[3,4-c]pyridine-1-carbonitrile (13). Pale yellow crystals: Yield 84%; mp 340 °C; Anal. calcd for C13H5I2N3O3: C, 30.90; H, 0.99; N, 8.32; found C, 30.92; H, 1.00; N, 8.34; IR (KBr, cm-1): 3374 (OH), 3277, 3228 (NH2), 2207 (CN), 1707, 1662 (CO

Palladium-catalyzed formation of oxazolidinones from biscarbamates: a mechanistic study

• Benan Kilbas and
• Metin Balci

Beilstein J. Org. Chem. 2011, 7, 246–253, doi:10.3762/bjoc.7.33

• , 56.08; H, 4.67; N, 3.85; S, 8.63. rel-(1R,2S,5R,6S)-2,5-Dihydroxybicyclo[4.1.0]hept-3-ene-7-exo-carbonitrile (14): To a magnetically stirred solution of endoperoxide 12 (1.00 g, 6.71 mmol) in MeOH/CHCl3 solution (30 mL), was added thiourea (513 mg, 6.75 mmol) over a 10 min period at room temperature and

• ), 21.5 (C-1 and C-6), 21.0 (–CH3), 3.6 (C-7); IR (νmax, cm−1) 2238, 1727, 1369, 1226, 1052, 1015, 990, 968. Anal. Calcd for C12H13NO4: C, 61.27; H, 5.57; N, 5.95. Found: C, 61.20; H, 5.44; N, 6.04. rel-(1R,2S,5R,6S)-2,5-Dihydroxybicyclo[4.1.0]hept-3-ene-7-endo-carbonitrile (18a): A solution of

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• hydrate afforded 5-amino-3-(pyrrol-2-yl)pyrazole-4-carbonitrile (50) (Scheme 12) [43]. Synthesis of 5-amino-3-aryl-1H-pyrazoles 53 has been reported using benzoylacetonitrile 51 as starting material. Substituted phenylhydrazines on reaction with substituted 1-aminocinnamonitriles 52, obtained from base

• that reaction is initiated on the vinyl ether (vinylamine) group of 74a/b to give 5-aminopyrazole-4-carbonitrile 76 through the intermediacy of 75 [59]. However, Elnagdi et al. [60] have reported that when ethyl hydrazinoacetate condenses with 74a or b, a change in regiochemistry occurs to yield 3

• -amino-4-cyanopyrazoles 77 (Scheme 20). Ethoxymethylenemalononitrile (R = OC2H5, R1 = H) 74c and bis(methylthio)- methylenemalononitrile (R = R1 = SCH3) 74d on condensation with hydrazine hydrate yield 5-aminopyrazole-4-carbonitrile 76 (R1 = H) and 5-amino-3-methylthiopyrazole-4-carbonitrile 76 (R1

Chromo- and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)

• Katja Hofmann,
• Ingolf Kahle,
• Frank Simon and
• Stefan Spange

Beilstein J. Org. Chem. 2010, 6, No. 79, doi:10.3762/bjoc.6.79

• chromophoric and fluorescent carbonitrile-functionalized poly(vinyl amine) (PVAm) and PVAm/silica particles were synthesized by means of nucleophilic aromatic substitution of 8-oxo-8H-acenaphtho[1,2-b]pyrrol-9-carbonitrile (1) with PVAm in water. The water solubility of 1 has been mediated by 2,6-O-β

• model compound and the carbonitrile-functionalized PVAm were studied and interpreted using the empirical Kamlet–Taft solvent parameters π* (dipolarity/polarizability), α (hydrogen-bond donating capacity) and β (hydrogen-accepting ability) in terms of the linear solvation energy relationship (LSER). The

• solvent-independent regression coefficients a, b and s were determined using multiple linear correlation analysis. It is shown, that the chains of the polymer have a significant influence on the solvatochromic behavior of 1-P. The structure of the carbonitrile 1-Si bound to polymer-modified silica

Diastereoselective and enantioselective reduction of tetralin- 1,4-dione

• E. Peter Kündig and
• Alvaro Enriquez-Garcia

Beilstein J. Org. Chem. 2008, 4, No. 37, doi:10.3762/bjoc.4.37

• -trimethylsiloxy-4-oxotetralin-1-carbonitrile (10) as protected equivalent of dione 2. Slow addition over 2 h of a THF solution of ketone 10 to a solution of BH3·THF (0.6 equiv) and catalyst 8 in THF at −30 °C gave, after MeOH quenching and TBAF deprotection, (−)-9 in 85% yield and 95% ee (Scheme 6). Cyanohydrin

The role of an aromatic group in remote chiral induction during conjugate addition of α-sulfonylallylic carbanions to ethyl crotonate

• Shlomo Levinger,
• Ranjeet Nair and
• Alfred Hassner

Beilstein J. Org. Chem. 2008, 4, No. 32, doi:10.3762/bjoc.4.32

• -carbonitrile was indicated by formation of a 10-tert-butyl derivative on reaction with tert-butylmagnesium chloride [9]. However, since iminium ion intermediates are much more reactive than ketones [7], imines 8h and 8j were successfully reduced to the primary amines 6 upon treatment with sodium

Synthesis of (S)-1-(2-chloroacetyl)pyrrolidine- 2-carbonitrile: A key intermediate for dipeptidyl peptidase IV inhibitors

• Santosh K. Singh,
• Narendra Manne and
• Manojit Pal

Beilstein J. Org. Chem. 2008, 4, No. 20, doi:10.3762/bjoc.4.20

• -carbonitrile was achieved. Reaction of L-proline with chloroacetyl chloride was followed by conversion of the carboxylic acid moiety of the resulting N-acylated product into the carbonitrile via the corresponding amide intermediate. The synthesized pyrrolidine derivative was utilized to prepare DPP-IV

• inhibition of DPP-IV and (ii) chemical stability adequate for oral administration [6] (Figure 2). Chemically, incorporation of a 2(S)-cyanopyrrolidine moiety into a molecule can be carried out by using (S)-1-(2-chloroacetyl)pyrrolidine-2-carbonitrile (6) as a reactant. Thus, compound 6 has become a widely

• (2S)-{[(3-hydroxyadamantan-1-yl)amino]acetyl}-pyrrolidine-2-carbonitrile (2) was prepared in 50% yield by reacting the intermediate 6 with 3-hydroxy-1-aminoadamantane (10) in the presence of K2CO3 at room temperature according to the known procedure (Scheme 3) [6]. Conclusion In conclusion, we have