- DIBENZOTHIOPHENE SALT AS ALKYNYLATING AND CYANATING AGENT
-
The present invention describes a new alkynylation and cyanation agent, as well as its preparation and use to introduce nitrile (cyano) or alkyne groups into chemical target molecules by means of an electrophilic reaction. To enable an electrophilic reaction, the chemical backbone of dibenzothiophene was used.
- -
-
Paragraph 0098
(2021/08/27)
-
- Synthesis of nitriles via the iodine-mediated dehydrosulfurization of thioamides
-
A simple general method for the synthesis of nitriles using the inexpensive and easy to handle iodine (I2) is described herein. The reaction of thioamides with I2 in the presence of triethylamine at room temperature under aerobic conditions afforded various nitriles bearing aryl, vinyl, and alkyl groups in good-to-excellent yields. This method was also effective for conversion from thioureas to cyanamides.
- Murata, Yuki,Iwasa, Hitomi,Matsumura, Mio,Yasuike, Shuji
-
p. 679 - 681
(2020/07/30)
-
- 5-(Cyano)dibenzothiophenium Triflate: A Sulfur-Based Reagent for Electrophilic Cyanation and Cyanocyclizations
-
The synthesis of 5-(cyano)dibenzothiophenium triflate 9, prepared by activation of dibenzo[b,d]thiophene-5-oxide with Tf2O and subsequent reaction with TMSCN is reported, and its reactivity as electrophilic cyanation reagent evaluated. The scalable preparation, easy handling and broad substrate scope of the electrophilic cyanation promoted by 9, which includes amines, thiols, silyl enol ethers, alkenes, electron rich (hetero)arenes and polyaromatic hydrocarbons, illustrate the synthetic potential of this reagent. Importantly, Lewis acid activation of the reagent is not required for the transfer process. We additionally report herein biomimetic cyanocyclization cascade reactions, which are not promoted by typical electrophilic cyanation reagents, demonstrating the superior ability of 9 to trigger challenging transformations.
- Li, Xiangdong,Golz, Christopher,Alcarazo, Manuel
-
supporting information
p. 9496 - 9500
(2019/06/27)
-
- Tris(3,5-dimethylpyrazolyl)methane copper(I) complexes featuring one disubstituted cyanamide ligand
-
The complexes [Cu{HC(3,5-Me2pz)3}(NCNR2)][BF4] (1–8; R2 = Me2 1, Et2 2, C5H10 3, C4H8O 4, C4H8 5, C3H
- Melekhova, Anna A.,Novikov, Alexander S.,Dubovtsev, Alexey Yu.,Zolotarev, Andrey A.,Bokach, Nadezhda A.
-
-
- Synthesis, structure activity relationship, radiolabeling and preclinical evaluation of high affinity ligands for the ion channel of the N-methyl-d-aspartate receptor as potential imaging probes for positron emission tomography
-
The N-methyl-d-aspartate receptor (NMDAr) is involved in many neurological and psychiatric disorders including Alzheimer's disease and schizophrenia. Currently, it is not possible to assess NMDAr availability in vivo. The purpose of this study was to develop a positron emission tomography (PET) ligand for the NMDAr ion channel. A series of di- and tri-N-substituted diarylguanidines was synthesized. In addition, in vitro binding affinity for the NMDAr ion channel in rat forebrain membrane fractions was assessed. Compounds 10, 11 and 32 were radiolabeled with either carbon-11 or fluorine-18. Ligands [11C]10 and [18F]32 were evaluated ex vivo in B6C3 mice. Biodistribution studies showed higher uptake of [11C]10 and [18F]32 in forebrain regions compared with cerebellum. In addition, for [11C]10 54% and for [18F]32 70% of activity in the brain at 60 min was due to intact tracer. Pre-treatment with MK-801 (0.6 mg·kg-1, ip) slightly decreased uptake in NMDAr-specific regions for [18F]32, but not for [11C]10. As such [18F]32 has the best characteristics as a PET tracer for the ion channel of the NMDAr.
- Klein, Pieter J.,Christiaans, Johannes A.M.,Metaxas, Athanasios,Schuit, Robert C.,Lammertsma, Adriaan A.,Van Berckel, Bart N.M.,Windhorst, Albert D.
-
p. 1189 - 1206
(2015/03/04)
-
- Copper-catalyzed one-pot synthesis of unsymmetrical arylurea derivatives via tandem reaction of diaryliodonium salts with N -arylcyanamide
-
An efficient "one-pot" approach to multiple substituted ureas from N-arylcyanamide and diaryliodonium salts has been presented. The two-step procedure involved the weak base-promoted chemoselective arylation of secondary amines with diaryliodonium and Cu-catalyzed nucleophilic addition of N-arylcyanamide with second diaryliodonium. The diverse unsymmetrical arylureas were obtained in up to 91% yield for 29 examples.
- Li, Pengfei,Cheng, Guolin,Zhang, Hong,Xu, Xianxiang,Gao, Jingyuan,Cui, Xiuling
-
p. 8156 - 8162
(2015/03/18)
-
- Nickel-catalyzed [2+2+2] cycloaddition of diynes and cyanamides
-
A variety of bicyclic N,N-disubstituted 2-aminopyridines have been prepared from diynes and cyanamides by nickel-catalyzed [2+2+2] cycloaddition reactions. The reactions proceeded at room temperature with low catalyst loading to afford 2-aminopyridines in
- Stolley, Ryan M.,MacZka, Michael T.,Louie, Janis
-
experimental part
p. 3815 - 3824
(2011/09/16)
-
- HETEROCYCLIC DERIVATIVE HAVING INHIBITORY ACTIVITY ON TYPE-I 11 -HYDROXYSTEROID DEHYDROGENASE
-
Disclosed is a compound which is useful as an 11β-hydroxysteroid dehydrogenase type 1 inhibitor. A compound represented by the formula: its pharmaceutically acceptable salt, or a solvate thereof, wherein X is O or S, a broken line and a wavy line represent the presence or the absence of a bond, (i) when a broken line represents the presence of a bond, a wavy line represents the absence of a bond, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, (ii) when a broken line represents the absence of a bond, a wavy line represents the presence of a bond, R1 and R4 are each independently hydrogen, halogen or the like, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, and R5 and R6 are each independently hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like.
- -
-
Page/Page column 34
(2010/08/07)
-
- 1-Cyanoimidazole as a mild and efficient electrophilic cyanating agent
-
formula presented A mild and high-yielding cyanating reaction of amine, sulfur, and carbanion nucleophiles is reported here using 1-cyanoimidazole as an electrophilic cyanating agent.
- Wu, Yong-Qian,Limburg, David C.,Wilkinson, Douglas E.,Hamilton, Gregory S.
-
p. 795 - 797
(2007/10/03)
-
- Modification of the Tiemann rearrangement: One-pot synthesis of N,N-disubstituted cyanamides from amidoximes
-
A three-stage one-pot synthetic procedure for transformation of amidoximes to N,N-disubstituted cyanamides in 70-92% yield is described.
- Bakunov, Stanislav A.,Rukavishnikov, Alexey V.,Tkachev, Alexey V.
-
p. 1148 - 1159
(2007/10/03)
-
- Preparation and characterisation of N,N-disubstituted 2-amino-selenazoles
-
As a result of checking suited methods for preparing N,N-disubstituted 2-amino-selenazoles 14 as a nearly unknown class of highly reactive selenazoles a simple route starting from N,N-disubstituted selenoureas 12 has been elaborated and used for the synthesis of a series of these compounds. The necessary selenium-containing starting compounds 12 are available from N,N-disubstituted cyanamides 18 and hydrogen selenide.
- Keil, Dietmar,Hartmann, Horst
-
p. 169 - 184
(2007/10/03)
-
- Acidity and N-methylation of N-aryl-N′-cyanoguanidines
-
Acid dissociation constants in water have been determined for proton loss from a series of N-aryl-N′-cyanoguanidines 1. Treatment of the same compounds with a strong base, butyllithium, followed by excess methyl iodide leads to successive N-methylation to yield mono-, di- and tri-methylated N-aryl-N′-cyanoguanidines. The mechanism of the methylation is discussed.
- Cunningham, Ian D.,Cox, Brian G.,Wan, Nan Chi,Povey, David C.,Smith, Gallienus W.
-
p. 693 - 697
(2007/10/03)
-
- Comparison of chemical and electrochemical reduction of cyanamides:an exmple of cathodic decyanation
-
Most disubstituted cyanamides exhibit a very low cathodic activity and are therefore difficult to reduce.However, the cathodic cleavage of diarylcyanamides can be carried out directly and leads to the corresponding diarylamine; the action of sodium causes the same cleavage.Alkylarylcyanamides display no cathodic step, but can be reduced indirectly by redox catalysis; this allows the determination of the standard potential corresponding to the first electron transfer.The macroscale electrolysis, in the presence of the catalyst, leads to the alkylarylamine by cleavage, whereas the action of sodium gives mainly a cyanoguanidine.Dialkylcyanamides are electroreducible neither directly, nor indirectly, whereas by action of sodium they trimerize almost quantitatively into triazines. Key words: cyanamide, decyanation, electroreduction, redox catalysis.
- Cariou, Michel,Simonet, Jacques
-
p. 861 - 864
(2007/10/02)
-
- 2-(N,N-Disubstituted Amino)thiazoles with Electron-withdrawing Groups at Position 5: Prepaeation and Investigation on Structural Features
-
A convenient procedure for preparing N-mono- and NN-di-substituted cyanamides from cyanogen bromide has been developed.N,N-Disubstituted thioureas, obtained from the cyanamides, were condensed with α-bromo-α-cyanoketones to give 5-cyano-2-(N,N-disubstituted amino)thiazoles and with α-bromo-ketones to give 2-(N,N-disubstituted amino)thiazoles.Substitution in the latter products afforded 5-trifluoroacetyl- and 5-nitro-2-(N,N-disubstituted amino)thiazoles; nitration is greatly facilitated by the presence of a 4-aryl group.The average values of the barriers of rotation of the barriers to rotation of the 2-NR2 groups (ΔG298) in the 5-substituted thiazoles were established by variable temperature 1H n.m.r. spectrometry to be 57.4 kJ mol -1 (5-NO2), 56.2 (5-COCF3), and 51.5 (5-CN).I.r. examination showed that the 5-trifluoroacetyl compounds adopt one rotational form preferentially; this is probably the carbonyl O,S-syn-conformation.
- Birkinshaw, Timothy N.,Gillon, David W.,Harkin, Shaun A.,Meakins, G. Denis,Tirel, Malkom D.
-
p. 147 - 153
(2007/10/02)
-
- Synthesis of the Heteroaromatic Selenatriazole Ring System. 5-Amino-1,2,3,4-selenatriazoles
-
The synthesis of 5-amino-1,2,3,4-selenatriazoles, derivatives of the hitherto unknown selenatriazole ring system, is described.Reaction between bis(N,N-disubstituted selenocarbamoyl)selenides and azide ion gives the title compounds in good yield.The reactions of 4,4-dialkylselenosemicarbazides with nitrous acid or an aza-transfer reagent also lead to aminoselenatriazoles.Disubstituted aminoselenatriazoles are thermally unstable decomposing with formation of disubstituted cyanamides, nitrogen and selenium. 5-(Diethylamino)selenatriazole (half-life ca. 180 h in CHCL3 at 20 deg C) is thermally more stable than 5-(methylphenylamino)selenatriazole. 5-(Alkylamino)selenatriazoles decompose to hydrazoic acid and an isoselenocyanate, and evidence for their formation was only obtained indirectly.
- Jacobsen, Mogens,Henriksen, Lars,Holm, Arne
-
p. 585 - 588
(2007/10/02)
-
- The Dehydration of Ureas by Two-Phase Dichlorocarbene Reaction, a Synthetic Access to Substituted Cyanamides
-
A wide variety of N,N-disubstituted ureas are dehydrated in the CHCl3/NaOH catalytic two-phase system under mild conditions.The sequence of urea-transamidation and dehydration thus offers a profitable approach to aprotic cyanamides.Among various tested PT-catalysts tertiary amines prove to be the most efficient and favourable ones.Tertiary amines may also be used advantageously in the transformation of carboxylic amides and thioamides to the corresponding nitriles.The application of the same technique is less suitable in the case of N-mono-substituted ureas, N,N'-disubstituted ureas as well as N(dialkylaminomethylidene)ureas, because consequent reactions of the primarily formed cyanamides predominate.Problems concerning the dehydration mechanism are elucidated in terms of HMO-perturbation theory.
- Schroth, W.,Kluge, H.,Frach, R.,Hodek, W.,Schaedler, H. D.
-
p. 787 - 802
(2007/10/02)
-
- Some Extensions of von Braun (BrCN) Reaction on Organic Bases: Part II
-
Extensions of von Braun Cyanogen bromide reaction on Ephedra alkaloids and simpler bases have resulted in synthesis of substituted oxazolidines and a whole series of nitrogen analogues of ephedrine, desoxy ephedrine and simpler amines.The general applicability and limitations of such extension of the reaction are also discussed. - Key words: von Braun Cyanogen Bromide Reaction
- Malik, Abdul,Afza, Nighat,Siddiqui, Salimuzzaman
-
p. 512 - 518
(2007/10/02)
-
- A New General Synthesis of N-Mono- and N-Di-substituted 2-Aminothiazoles
-
Solutions of α-mercapto-ketone anions, generated from O-ethyl S-2-oxoethyl dithiocarbonates and piperidine, react with cyanamides to give 2-aminothiazoles with substituents on the heterocycle or the exo-nitrogen atom.
- Brown, Michael D.,Gillon, David W.,Meakins, G. Denis,Whitham, Gordon H.
-
p. 444 - 445
(2007/10/02)
-
- Isocyanoamines, R-NH-NC
-
Secondary isocyanoamines, R-NH-NC, are obtained by flash vacuum pyrolysis of 3-methyl-4-(arylhydrazono)isoxazol-5(4H)-ones.
- Wentrup, Curt,Winter, Hans-Wilhelm
-
p. 1045 - 1046
(2007/10/02)
-
- SUBSTITUENT EFFECT TREATMENT OF INTERACTIONS BETWEEN CONTIGUOUS FUNCTIONALITIES. IV. RESTRAINT TO PHENYL-NITROGEN CONJUGATIVE INTERACTION IN N-FUNCTIONALIZED N-METHYLANILINES
-
13C shifts at the para position in PhN(Me)X for 17 different substituents X serve as monitors for investigating, in correlative analysis, the nature and the extent of interactions occurring between the substituent X and the N-Me cavity.For the majority of substituent, X, partitioning of the nitrogen electron pair between the phenyl and the substituent is partially hampered because of the non-zero twist angle between the planes containing the phenyl ring and the Me-N-X fragment.As a consequence, relative to PhNHX, the interactions between the cavity and the substituents are increased in intensity, especially their mesomeric component, and, at the same time, para-13C shifts are displaced toward lower field.Evidence is also provided that possible H-bonding by the NH cavity of PhNHX with dimethyl sulphoxide does not appreciably influence the substituent electron demand determined previously.
- Bradamante, Silvia,Colombo, Silvana,Pagani, Giorgio A.,Roelens, Stefano
-
p. 357 - 364
(2007/10/02)
-