Reaction Of Cyanamide Research Articles

Could Purines Be Formed from Cyanamide and Cyanoacetylene in a Prebiotic Earth Environment?

Knowledge of prebiotic nucleobase formation is important for understanding the origin of contemporary genetics. Observation of nucleobase precursor radicals in previous impact laser plasma simulations of the late heavy bombardment period (FerusProc. Natl. Acad. Sci. U.S.A.2015, 112, 65725489115) points toward possible nucleobase formation through free-radical pathways. However, previously explored radical routes to nucleobase formation involve a large number of reaction steps, repetitive addition of precursors, and a number of chemical transformations. The possibility of competing side reactions under such conditions questions the feasibility of such pathways. In view of these shortcomings, the present work employs density functional theory to explore purine formation pathways through reaction of cyanamide and cyanoacetylene with radicals via a five-membered intermediate, 4-cyanoimidazole in the presence of ammonia. Our analysis reveals that the skeletal components of 4-cyanoimidazole can be solely obtained from cyanamide and cyanoacetylene via barrierless cyclization and a small number of reaction steps. In addition, the proposed mechanisms are characterized by a small number of precursors and low energy barriers and are thus likely feasible under extreme conditions on the prebiotic earth such as meteoritic impact during late heavy bombardment period. Overall, the present study underscores the importance of cyanamide and cyanoacetylene precursors in kinetically accessible routes to purine formation.

A numerical and experimental study of the decomposition pathways of guanidinium nitrate

The thermal decomposition behaviour of guanidinium nitrate (GN), an energetic material, was analysed using a combined experimental and computational approach. Simultaneous thermogravimetric analysis, Fourier transform infrared spectroscopy and mass spectrometry (TG-FTIR-MS) experiments were carried out at three different heating rates under closed and open crucible conditions. A two-stage decomposition process was observed, and the major gases evolved were found to be NH3, N2O, NO2 and CO2. Quantum mechanics based ab initio computations were performed to evaluate the possible decomposition pathways available for GN. Results indicate that decomposition of GN is not initiated in the condensed phase as the guanidinium cation and the nitrate anion are highly stable. The most likely mechanism involves isomerization of GN followed by a proton transfer in the gas phase to yield nitric acid and guanidine. These products then further react to form nitroguanidine (NQ) and H2O. NQ dissociates via several competing pathways to yield NH3, N2O, H2O and CO2. HNO3 decomposition can help explain NO2 formation. The residue left towards the end of TG can be attributed to dimerization and trimerization reactions of cyanamide.

ChemInform Abstract: A General and Mild Copper(I)‐Catalyzed Three‐Component Reaction of Cyanamides, Amines, and Diaryliodonium Triflates

Abstractto give guanidines in good yields

Prebiotic-Like Condensations of Cyanamide and Glyoxal: Revisiting Intractable Biotars.

We report a detailed investigation into the nature of products that are generated by the reactions of cyanamide and glyoxal, two small molecules of astrochemical and prebiotic significance, under different experimental conditions. The experimental data suggest that the formation of oligomeric structures is related in part to the formation of insoluble tholins in the presence of oxygen-containing molecules. Although oligomerization proceeds well in water, product isolation turned out to be impractical. Instead, solid precipitates were obtained easily in acetone. Crude mixtures have been thoroughly scrutinized by spectroscopic methods, in particular NMR and mass spectroscopy (ESI mode), which are all consistent with the generation of a few functional groups that are embedded into regular chains of five- and six-membered rings, thereby pointing to a supramolecular organization. Three different models of cross-condensation and chain growth are suggested. These synthetic explorations provide further insights into the formation of complex organic matter in interstellar scenarios and extraterrestrial bodies that might have played a pivotal role in chemical evolution.

A General and Mild Copper(I)‐Catalyzed Three‐Component Reaction of Cyanamides, Amines, and Diaryl­iodonium Triflates

AbstractA highly efficient copper‐catalyzed three‐component reaction of cyanamides, amines, and diaryliodonium triflates was developed for the synthesis of guanidines. The mild reaction accommodates both aromatic and aliphatic amines and provides the products in good yields with good functional group tolerance. Moreover, it was demonstrated that C–H activation of the arenes could be realized for the direct preparation of guanidines.

Application of supported Mn(iii), Fe(iii) and Co(ii) as heterogeneous, selective and highly reusable nano catalysts for synthesis of arylaminotetrazoles, and DFT studies of the products

M@Si/Al (where M = Mn(III), Co(II) and Fe(III) supported on nanosized SiO2/Al2O3) is applied as an efficient, highly reusable and heterogeneous catalyst for the regiospecific synthesis of 1-aryl-5-amino-1H-tetrazole in dimethylformamide (DMF) as a solvent. The arylaminotetrazoles were efficiently synthesized from the reaction of cyanamides and sodium azide in the presence of a catalytic amount of nano metal catalyst under thermal conditions. 1-Aryl-5-amino-1H-tetrazoles (B isomer) can be obtained from the arylcyanamides carrying electron releasing substituents on the aryl ring, while with electron withdrawing groups, 5-arylamino-1H-tetrazole (A isomer) will be obtained. The advantages of this method include high yields, relatively short reaction times, easy work-up, recovery and reusability of the catalyst and high TON of catalyst. The nano catalyst can be easily recovered and reused several times without considerable loss of activity. The quantum theoretical calculations for the synthesized components were performed by density functional theory (DFT) methods using the 6-31G basis set, geometry and thermodynamic parameters, frontier molecular orbitals (FMOs) as well as by using molecular electrostatic potentials (MEPs).

Nano Cerium Oxide as a Recyclable Catalyst for the Synthesis of N-Monosubstituted Ureas with the Aid of Acetaldoxime as an effective Water Surrogate

A new method for the synthesis of N-monosubstituted ureas has been developed by the reaction of cyanamides with acetaldoxime in the presence of nano cerium oxide as an efficient and recyclable catalyst.

Hydrogencyanamido bridged multinuclear copper(ii) complexes: from strong antiferromagnetic couplings to weak ferromagnetic couplings

In the presence of ammonia, the reactions of cyanamide and Cu(II) ions with different organic blocking ligands afford three hydrogencyanamido bridged dinuclear complexes: [(dmbpy)(4)Cu(2)(HNCN)](ClO(4))(3)·H(2)O (1, dmbpy = 4,4'-dimethyl-2,2'-bipyridine), [(phen)(4)Cu(2)(HNCN)](ClO(4))(3)·2H(2)O (2, phen = 1,10-phenanthroline) and [(bpy)(2)Cu(2)(HNCN)(2)(ClO(4))(2)] (3, bpy = 2,2'-bipyridine), respectively. However, using the di(2-pyridyl)ketone (dpk) ligand in similar experimental conditions, an interesting reaction between the hydrogencyanamido anion and dpk is observed. Using Cu(ClO(4))·6H(2)O or Co(ClO(4))·6H(2)O as the metal source, it gives the mixed bridged hexanuclear complex [(dpk·OMe)(4)(dpk·NCN)(2)Cu(6)(H(2)O)(2)](ClO(4))(4) (4), or the mononuclear complex [(dpk·OMe)(dpk·HNCN)Co](ClO(4))·2H(2)O (5), respectively. Their structures are characterized by single crystal X-ray diffraction analyses. Magnetic measurements reveal moderate antiferromagnetic interaction between the Cu(II) ions in complex 1, weak ferromagnetic coupling in complex 2, and strong antiferromagnetic interactions for complexes 3 and 4. The magnetostructural correlations of these complexes are discussed.

ChemInform Abstract: Reaction of Cyanamides with N‐Alkylnitrilium and N,N‐Dialkylcyanamidium Salts.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

On the Reaction of Cyanamides with N-Alkylnitrilium and N,N-Dialkylcyanamidium Salts

N-Alkylnitrilium and N,N-dialkylcyanamidium salts 1 and 2 undergo ene reactions with cyanamides 4 to afford 2-azoniaallene salts 7 and 9 in which the N-alkylnitrilium salts 1 react as the ene, and the cyanamides 4 react as the enophile components. Competing with the ene reaction, N-alkylnitrilium salts 1 undergo [2++2+2] cycloaddition to furnish triazinium salts 8. 2-Azoniaallene salts react with alcohols to afford alkoxy amino derivatives 10 and 12, which yield iminium salts 11 and ketals/acetals upon further reaction with alcohols. The constitution of the 2-azoniaallene 7 and 9 and triazinium salts 8 was secured by elemental analyses and spectral properties (IR and NMR).

Reaction of cyanamides with N,N-binucleophiles

Reactions of 4,6-dimethylpyrimidin-2-yl-and aroylcyanamides with benzene-1,2-diamine, ethylenediamine, cyclohexane-1,2-diamine, and naphthalene-1,8-diamine leads to 1H-benzimidazol-2-amine, imidazolidin-2-imine, perhydrobenzimidazol-2-imine, and 1H-perimidin-2-amine derivatives, respectively.

Reaction of cyanamide and their derivatives with (η 5-C 5H 5)Mn(CO) 3 and (η 5-C 5H 4CH 3)Mn(CO) 3

The reaction of cyanamide and its derivatives with the (η 5-C 5H 5)Mn(CO) 2(THF) and (η 5-C 5H 4CH 3)Mn(CO) 2(THF) complexes affords the cyanamide substituted complexes of types (η 5-C 5H 5)Mn(CO) 2(NCN(R′)(R″)) ( 2a– d) and (η 5-C 5H 4CH 3)Mn(CO) 2(NCN(R′)(R″)) ( 3a– e). All complexes were characterized by spectroscopy ( 1H, 13C NMR, IR), elemental and mass spectroscopy analysis. Complex 2b (η 5-C 5H 5)Mn(CO) 2(NCN(CH 3) 2) was additionally examined by single crystal X-ray structure determination.

Reactions of alkyl acetone-1,3-dicarboxylates with cyanamide and benzoylcyanamide

The reactions of cyanamide with dialkyl acetone-1,3-dicarboxylates in the presence of nickel acetylacetonate afforded alkyl 2-amino-4-hydroxy-6-oxo-1,6-dihydropyridine-3-carboxylates. The same compounds were obtained by intramolecular cyclization of adducts of acetone-1,3-dicarboxylates with benzoylcyanamide under the action of sodium alkoxides.

Nucleophilic substitution or dipolar 1,3-cycloaddition in reactions of cyanamide with 4-arylpyrimidine 1-oxides

Pyrimidine 1-oxides with cyanamide afforded 2-ureidopyrimidines as the result of the nucleophilic substitution of hydrogen, whereas the formation of similar 2-trichloroacetylaminopyrimidines occurs as dipolar 1,3-cycloaddition of the same oxides to trichloroacetonitrile under much more drastic conditions and in lower yields.

Preparation of N, N-unsubstituted selenoureas and thioureas from cyanamides

Reaction of cyanamides with LiAlHSeH and LiAlHSH in the presence of HCl in diethyl ether provided the corresponding N, N-unsubstituted selenoureas and thioureas in moderate to high yields, respectively.

Anion exchangers with alkyl substituted guanidyl groups: Gold sorption and Cu(II) coordination

Two methods of introducing guanidyl groups into polymer matrix were investigated in this work: the reaction of cyanamide (alkyl substituted cyanamides) and carbodiimides with amino groups in modified polystyrene. The new anion exchangers (AEG) with alkyl substituted guanidyl groups contain 1.5–2.3 mmol/g of ligands and exhibit high selectivity towards Au(CN) 2 − anions. From the solution containing 2 ppm of gold the sorption is as high as 30 mg/g. Furthermore, AEG reveal high affinity towards tetrachloroaurate anions. The log K in diluted solution is about 5. The values of gold sorption as dicyanoaurate or tetrachloroaurate anions on AEG with alkyl substituted hydrogen atoms in guanidyl groups is two–four times higher than sorption on anion exchangers synthesized previously by exchange of chlorine with guanidine or aminoguanidine. The EPR studies of Cu(II)-loaded AEG were undertaken to correlate the structural properties of the formed complexes with the nature of the ligands, the ligand concentration, water regain of the resins and pH.

Synthesis of the hindered N,N,N′-trisubstituted guanidine moiety of martinelline and martinellic acid

Hindered guanidines can be prepared by reaction of cyanamides with amines in hexafluoroisopropanol at 90–120°C. This sequence was used for preparing guanidinium acid 21 as a model for martinellic acid.

Darstellung und Charakterisierung von Rubidiumhydrogencyanamid/Synthesis and Characterization of Rubidium Hydrogen Cyanamide

The synthesis of RbHCN2 was carried out by reaction of cyanamide with rubidium amide in liquid ammonia. The crystal structure has been determinedo by x-ray powder methods (orthorhombic, P21,21,21, a = 7.299(1), b = 9.435(1), c = 9.420(1) Å; Z = 8). The anion is slightly bent (174°) and exhibits two different bond lengths (C-N: 1.17, HN-C: 1.31 Å).

Condensation of 2-aminobenzothiazoles with dimethylcyanamide

The addition of amine hydrochlorides to cyanamides is a standard method for the synthesis of substituted guanidines. I It was reported 2 that hydrochlorides of heterocyclic amines can be used in this reaction, and, e.g., heating (180 *C) of 3-amino-l ,2-benzoisothiazole hydrochlorides with an excess ofdimethyicyanamide (1) results in the formation of N,N-dimethyl-N'-(l ,2-benzoisot hiazolyl)guanidine. 3 We have unexpectedly found that the reaction of cyanamide 1 with 2-aminobenzothiazole hydrochlorides (2a) (or its 6-bromo-derivative 2b) under similar conditions is a more complicated process, viz., the condensation of two eyanamide molecules with two molecules of aminoazole hydrochloride (with the elimination of the dimethylamine hydrochloride and NH4CI). This results in previously unknown derivatives of 4-(benzothiazol2 y l ) i m i n o 2 d i m e t h y l a m i n o 4 H i , 3 , 5 t r i a z i n o [2,I-blbenzothiazole (3a,h) isolated in moderate yields.

Reactions of cyanamide, dicyandiamide and related cyclic azines in high temperature water

Cyanamide, dicyandiamide, and the related cyclic azines (melamine, ammeline, ammelide, and cyanuric acid) were reacted in water at 100–300 °C in a sealed 316 SS tube (275 bar) for the purpose of characterizing the hydrothermolysis chemistry of cyanamide. The conversion of cyanamide to dicyandiamide dominates at 100–175 °C. At 175–250 °C, when the reaction times are shorter than 15 min, the major pathway is hydrolysis of the cyanamide-dicyandiamide mixture to CO 2 and NH 3. A minor pathway is cyclization to higher azines (melamine, ammeline, ammelide and cyanuric acid). Above about 225 °C, hydrolysis of these cyclic azines to aqueous NH 3 and CO 2 occurs in a relative ratio which depends on the particular cyclic azine, and, to an extent, which increases with temperature. At 300 °C the conversion of all compounds to CO 2 and NH 3 is complete in 10 min. The hydrothermolysis chemistry of cyanamide and urea are compared.