Cyanomethyl Research Articles

The CH$_\mathsf{2}$CN- molecule: carrier of the $\mathsf{\lambda}$8037 diffuse interstellar band?

The hypothesis that the cyanomethyl anion CH2CN is responsible for the relatively narrow di use interstellar band (DIB) at 8037:8 0:15 A is examined with reference to new observational data. The 0 0 absorption band arising from the 1 B1 ˜ X 1 A 0 transition from the electronic ground state to the first dipole-bound state of the anion is calculated for a rotational temperature of 2.7 K using literature spectroscopic parameters and results in a rotational contour with a peak wavelength of 8037.78 A. By comparison with di use band and atomic line absorption spectra of eight heavily-reddened Galactic sightlines, CH2CN is found to be a plausible carrier of the 8037 di use interstellar band provided the rotational contour is Doppler-broadened with a b parameter between 16 and 33 km s 1 that depends on the specific sightline. Convolution of the calculated CH2CN transitions with the optical depth profile of interstellar Tiii results in a good match with the profile of the narrow 8037 DIB observed towards HD 183143, HD 168112 and Cyg OB2 8a. The rotational level populations may be influenced by nuclear spin statistics, resulting in the appearance of additional transitions from Ka = 1 of ortho CH2CN near 8025 and 8050 A that are not seen in currently available interstellar spectra. For CH2CN to be the carrier of the 8037 di use interstellar band, either a) there must be mechanisms that convert CH2CN from the ortho to the para form, or b) the chemistry that forms CH2CN must result in a population of K 00 levels approaching a Boltzmann distribution near 3 K.

Unexpected cleavage of the N–N bond in the reactions of 3-pyrazolidinone-1-azomethine imines with HCN

Treatment of (1 Z,4 R ∗,5 R ∗)-1-arylmethylidene-4-benzamido-5-phenylpyrazolidin-3-one 1-azomethine imines 4a– d with potassium cyanide in the presence of acetic acid resulted in addition of HCN to the exocyclic C N double bond followed by β-eliminative N–N single bond cleavage (ring opening) to give the N-[(1 R ∗,2 R ∗)-3-amino-2-benzamido-3-oxo-1-phenylpropyl]benzimidoyl cyanides 6a– d in 28–85% yields. Reaction of dipole 4e with HCN furnished stable intermediate, (1′ S ∗,4 R ∗,5 R ∗)-4-benzamido-1-[cyano(mesityl)methyl]-5-phenylpyrazolidin-3-one ( 5e), in 76% yield. The structure of compound 6c was determined by X-ray diffraction.

An Electrochemical Alternative Approach to the Cyclization of Alkynes Bearing Proximate Malonyl Moieties

AbstractA versatile alternative approach to the synthesis of butenolides, quinolones and 3‐pyrrolin‐2‐ones has been achieved by galvanostatic electrolysis of MeCN/TEATFB solutions and subsequent addition of the cathodic solution to alkynes bearing proximate malonyl moieties. The electrogenerated cyanomethyl anion permits the formation of the reactive anionic intermediates under mild conditions, avoiding the need to use classical bases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Synthesis of (S)‐cyano(3‐phenoxyphenyl)methyl (1R,3R)‐ 3‐[(1Z)‐2‐chloro‐3,3,3‐trifluoro‐1‐propenyl]‐2,2‐dimethylcyclopropanecarboxylate‐1‐14C

Abstractγ‐Cyhalothrin (1a), (S)‐cyano(3‐phenoxyphenyl)methyl (1R,3R)‐3‐[(1Z)‐2‐chloro‐3,3,3‐trifluoro‐1‐propenyl]‐2,2‐dimethylcyclopropanecarboxylate, is a single‐isomer, synthetic pyrethroid insecticide marketed by Pytech Chemicals GmbH, a joint venture between Dow AgroSciences and Cheminova A/S. As a part of the registration process there was a need to incorporate a carbon‐14 label into the cyclopropyl ring of this molecule. A high yielding radiochemical synthesis of γ‐cyhalothrin was developed from readily available carbon‐14 labeled N‐t‐Boc protected glycine. This seven step synthesis, followed by a preparative normal phase HPLC separation of diastereomers, provided 21.8 mCi of γ‐cyhalothrin‐1‐14C (1b) with >98% radiochemical purity. Copyright © 2007 John Wiley & Sons, Ltd.

Cyano(ethoxycarbonothioylthio)methyl Benzoate: A Novel One‐Carbon Radical Equivalent.

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, please click on HTML or PDF.

Alteration in the Binding Property of a Laterally Nonsymmetric Aza Cryptand toward CuII, AgI, and TlIIons upon Derivatization with a Cyanomethyl Group

AbstractThe laterally nonsymmetric aza cryptandLoreadily forms mononuclear inclusion complexes with metal ions like CuII, NiII, AgI, TlI, and so forth. However, when the secondary amines present in the three bridges are substituted by a cyanomethyl group to yield a new cryptandL, its metal‐binding properties are drastically altered. Thus, whileLobinds AgIat the tren end, showing AgN4coordination, inL, the bridgehead nitrogen atoms are pulled inside to form a two‐coordinate complex of AgIand none of the O or N atoms present in the three bridges are involved in coordination. This is probably the first example where the two bridgehead atoms are pulled inside to the maximum to bind the metal ion. Likewise, the TlIion shows TlN4coordination withLo, while inLit is loosely bound at the tren end, showing TlN3coordination. Upon treatment with a AgIsalt, the TlIcan be replaced almost instantaneously. On the other hand, with copper(II) tetrafluoroborate salt in moist DMF, two of the cyanide groups inLare converted to carboxylic acid groups and bind the metal ion from outside. The CuIIion in this complex shows distorted octahedral coordination where the two O atoms from the two carboxylic acid groups and the two corresponding N atoms in the two bridges are bound equatorially. The two axial sites are occupied by the nearby bridgehead N atom and the O atom of a DMF molecule. All five complexes and the free ligands are characterized by spectroscopic and X‐ray crystallographic studies. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Cyclodimerization of 3,2-Stevens rearrangement products of 1,9-bisammonium salts containing a 5-oxanonane-2,7-diyne-1,9-diyl group

1,9-Bisdimethylammonium salts containing a 5-oxanonane-2,7-diyne-1,9-diyl along with alkoxycarbonylalkyl group, undergo double 3,2-Stevens rearrangement under the action of corresponding sodium alcoholates to form allene diamino esters whose prototropic isomerization under the action of dilute HCl gives rise to diketo diesters. The latter undergo 1,4-alcohol elimination under the reaction conditions and yield diene keto esters that cyclodimerize into cyclohexene derivatives. The bisammonium salt with a cyanomethyl group rearranges to form an allene dinitrile, which isomerizes into a diene compound.

Electrogenerated Cyanomethyl Anion in Organic Synthesis: Formation of Four- and Five-membered Heterocycles

not Available.

Cyano(ethoxycarbonothioylthio)methyl Benzoate: A Novel One-Carbon Radical Equivalent

[reaction: see text] Cyano(ethoxycarbonothioylthio)methyl benzoate 3 has been prepared and shown to be an excellent one-carbon radical equivalent that can be applied for the introduction of an acyl unit via xanthate transfer radical addition to olefins. The corresponding adducts can be further elaborated. A rare 1,5-nitrile translocation was also observed during the study.

Dipotassium-Hydrogen-Phosphate-Powder-Catalyzed Stereoselective C-Vinylation of Diphenylacetonitril

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates by diphenylacetonitril, leads to the vinyltriphenylphosphonium salts, which undergo a Michael addition reaction with a conjugate base to produce the corresponding stabilized phosphorus ylides. Dipotassium hydrogen phosphate powder was found to catalyze the conversion of the stabilized phosphorus ylides to dialkyl(Z)-2-[cyano (diphenyl)methyl]-2-butenedioates under thermal and microwave conditions in a solventless system.

Electrogenerated Cyanomethyl Anion in Organic Synthesis. Synthesis of 1,3- Oxazolidine-2,4-Diones

Electrogenerated Cyanomethyl Anion in Organic Synthesis. Synthesis of 1,3- Oxazolidine-2,4-Diones

The Electrogenerated Cyanomethyl Anion in Organic Synthesis

AbstractFor Abstract see ChemInform Abstract in Full Text.

Potential energy surface survey towards prediction of a new radical [H 2,Si,C,N

While the cyanomethyl radical CH 2CN has been detected in space and extensively studied, the silicon-analogue [H 2,Si,C,N] is still unknown even in laboratory and has never been studied in spite of experimental expectation. Here, we present a detailed theoretical investigation on the doublet [H 2,Si,C,N] potential energy surfaces including 21 minimum isomers and 44 interconversion transition states at the Gaussian-3//B3LYP/6-31G(d) and CSB-QB3 levels. The former three low-lying isomers within 10 kcal/mol are bent H 2Si C N| 1 (0.0 kcal/mol), linear H 2CNSi 3 (0.8) with resonating structures H 2C N Si| ↔ H 2C N Si| and bent H 2Si N C| 2 (6.5), for which high conversion barriers exist between them. Additionally, five isomers HCNSiH 7 (26.6), H 2NCSi 5 (30.6), H 2CSiN 4 (58.5), HCSiNH 10a (63.5) and 10b (60.1) each have considerable barriers. Interesting features such as the intra-and inter-donor–acceptor bonding, the cumulenic silicon-bonding and silylene are revealed. Future experimental characterization and astrophysical detection of the eight [H 2,Si,C,N] isomers, especially the former three low-lying species 1, 3 and 2, are strongly recommended. The accurate spectroscopic data at the QCISD/6-311G(d,p) level are provided.

Fluorescent substrates for soluble epoxide hydrolase and application to inhibition studies

Inhibition of the mammalian soluble epoxide hydrolase (sEH) is a promising new therapy in the treatment of disorders resulting from hypertension and vascular inflammation. A spectrophotometric assay (4-nitrophenyl- trans-2,3-epoxy-3-phenylpropyl carbonate, NEPC) is currently used to screen libraries of chemicals; however this assay lacks the required sensitivity to differentiate the most potent inhibitors. A series of fluorescent α-cyanoester and α-cyanocarbonate epoxides that produce a strong fluorescent signal on epoxide hydrolysis by both human and murine sEH were designed as potential substrates for an in vitro inhibition assay. The murine enzyme showed a broad range of specificities, whereas the human enzyme showed the highest specificity for cyano(6-methoxy-naphthalen-2-yl)methyl trans-[(3-phenyloxiran-2-yl)methyl] carbonate. An in vitro inhibition assay was developed using this substrate and recombinant enzyme. The utility of the fluorescent assay was confirmed by determining the IC 50 values for a series of known inhibitors. The new IC 50 values were compared with those determined by spectrophotometric NEPC and radioactive tDPPO assays. The fluorescent assay ranked these inhibitors on the basis of IC 50 values, whereas the NEPC assay did not. The ranking of inhibitor potency generally agreed with that determined using the tDPPO assay. These results show that the fluorescence-based assay is a valuable tool in the development of sEH inhibitors by revealing structure–activity relationships that previously were seen only by using the costly and labor-intensive radioactive tDPPO assay.

The Electrogenerated Cyanomethyl Anion in Organic Synthesis

The Electrogenerated Cyanomethyl Anion in Organic Synthesis

Laboratory Microwave Spectroscopy of the Cyanomethyl Radical, CH2CN

The microwave spectrum of the cyanomethyl radical (CH2CN) in its ground electronic state ( 2B1) has been observed for the lowest three rotational transitions (N = 1-0 to 3-2) using a Fourier-transform microwave spectrometer in combination with a pulsed-discharge nozzle. The observed frequencies may thus be used as precise rest frequencies of the radical with a frequency accuracy of several kilohertz. A total of 92 hyperfine components of the five rotational transitions for both ortho (Ka = 0) and para (Ka = 1) species have been measured, leading to refinement of the hyperfine coupling constants for the nitrogen and hydrogen nuclei of the molecule. One of the transition frequencies for the para species coincides within our experimental accuracy to U39927, observed in the spectral line survey toward TMC-1. This study has confirmed that the cyanomethyl radical has a permanent dipole of approximately 3.5-4 D, which differs from the value reported previously.

Interconversion between syn and anti Conformations of 1,3-Bis(O-cyanomethyl)-p-tert-butylthiacalix[4]arene

Abstract 1,3-Bis(O-cyanomethyl)-p-tert-butylthiacalix[4]arene (5) has been found to interconvert between syn and anti conformations in solution. The equilibrium shifts toward the anti form with increasing solvent polarity. In the solid state, it adopts a pinched cone conformation with the syn arrangement of the cyanomethyl groups. Reduction of the equilibrium mixture of 5 with LiAlH4 gives only anti stereoisomer of 1,3-bis(O-aminoethyl)-p-tert-butylthiacalix[4]arene.

Fluoride-induced chemiluminescent decomposition of 1,2-dioxetanes bearing a phenyl moiety substituted with a methyl having an electron-withdrawing groupElectronic supplementary information (ESI) available: experimental section. See http://www.rsc.org/suppdata/cc/b2/b210857g/

A new type of dioxetane bearing a 3-(cyanomethyl)phenyl (1a), 3-(methoxycarbonylmethyl)phenyl (1b), 3-(benzoylmethyl)phenyl (1c), or 3-[cyano(methoxycarbonyl)methyl]phenyl group (1d) decomposed through an intermediary dioxetane bearing a benzylic carbanion to afford crimson to yellow light on treatment with TBAF in DMSO.

Synthesis and Properties of 6‐Amino‐7‐hetaryl‐5‐R‐5H‐pyrrolo[2,3‐b]pyrazine‐2,3‐dicarbonitriles.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Non-classical antifolates, 5-( N-phenylpyrrolidin-3-yl)-2,4,6-triaminopyrimidines and 2,4-Diamino-6(5 H)-oxopyrimidines, synthesis and antitumor studies

A series of non-classical antifolates, namely 5-( N-phenylpyrrolidin-3-yl)-2,4,6-triaminopyrimidines ( 25a– i) and 2,4-diamino-( N-phenylpyrrolidin-3-yl)-6(5 H)-oxopyrimidines ( 26a, b, c, f, h, i) was synthesized and evaluated for their in vitro cytotoxicity. Reacting aniline derivatives with 1,4-dibromo-2-butanol gave 1-phenyl-3-pyrrolidinols ( 19a-– i), which were oxidized to pyrrolidin-3-ones ( 20a– i). The Knoevenagel reaction of 20a– i with malononitrile or ethyl cyanoacetate gave 3-(dicyanomethylene)- ( 21a– i) and 3-[cyano(ethoxycarbonyl)methylene]-pyrrolidines ( 22a, b, c, f, h, i), respectively, which were subsequently reduced to the corresponding 3-(dicyano)methyl- or 3-[cyano(ethoxycarbonyl)methyl)]pyrrolidines ( 23a– i and 24a, b, c, f, h, i, respectively). Condensation of either 23a– i or 24a, b, c, f, h, i with guanidine afforded the target compounds. The cytotoxicity of these compounds was evaluated based on their ability to inhibit various human tumors (human colon adenocarcinoma COLO 205, lung carcinoma H23 and its adriamycin resistant cell line H23/0.3, T-cell leukemia MOLT-4, promyelocytic leukemia HL-60, and T-cell acute lymphocytic leukemia CCRF-CEM) cell growth in culture. These studies revealed that the 2,4,6-triaminopyrimidine derivatives were more cytotoxic than the 2,4-diamino-6(5 H)-oxopyrimidine counter parts, in which the latter was inactive in all testing systems. The 2,4,6-triaminopyrimidine derivatives bearing halogen substituent on the phenyl ring ( 25f, h, i) were cytotoxic in all cultured leukemia cell growth. Among these compounds, 5-(4-fluoro and 4-chlorophenyl)-2,4,6-triaminopyrimidines ( 25e and 25h, respectively) were more potent than methotrexate (MTX) in inhibiting of H23/0.3 cell growth. These compounds inhibit the folate metabolic pathways as indicated by tritium release from [5- 3H]deoxyuridine in MTX sensitive human fibrosarcoma HT-1080 cells. Dihydrofolate reductase is the major target for 25f, h, i, as shown by leucovorin (LV) rescue of MTX cytotoxicity.