13752-78-8Relevant articles and documents
Synthesis, Chemistry, and Photochemistry of Methylcyanobutadiyne in the Context of Space Science
Kerisit, Nicolas,Rouxel, Cédric,Colombel-Rouen, Sophie,Toupet, Lo?c,Guillemin, Jean-Claude,Trolez, Yann
, p. 3560 - 3567 (2016/05/24)
An alternative preparation of methylcyanobutadiyne (MeC5N), a molecule present in the interstellar medium, was established in order to circumvent tedious steps from previous methods. The possibility of forming methylcyanoacetylene and MeC5N by gas-phase photolysis was evaluated from relevant acetylene derivatives in the context of space science. The reactivity of MeC5N toward simple nucleophiles was investigated. The exclusive formation of E adducts was observed, together with a solvent dependence for the regioselectivity of the addition.
3-pyridazinylnitrenes and 2-pyrimidinylnitrenes
Torker, Sebastian,Kvaskoff, David,Wentrup, Curt
, p. 1758 - 1770 (2014/03/21)
Mild flash vacuum thermolysis of tetrazolo[1,5-b]pyridazines 8T generates small amounts of 3-azidopyridazines 8A (8aA, IR 2145, 2118 cm-1; 8bA, 2142 cm-1). Photolysis of the tetrazoles/azides 8T/8A in Ar matrix generates 3-pyridazinylnitrenes 9, detected by ESR spectroscopy (9a: D/hc = 1.006; E/hc = 0.003 cm-1). Cyanovinylcarbenes 11, derived from 4-diazobut-2-enenitriles 10, are also detected by ESR spectroscopy (11a: D/hc = 0.362; E/hc = 0.021 cm-1). Carbenes 11 rearrange to cyanoallenes 12 and 3-cyanocyclopropenes 13. Triazacycloheptatetraenes 20 were not observed in the photolyses of 8. Photolysis of tetrazolo[1,5-a]pyrimidines/2- azidopyridmidines 18T/18A in Ar matrices at 254 nm yields 2-pyrimidinylnitrenes 19, observable by ESR, UV, and IR spectroscopy (19a: ESR: D/hc = 1.217; E/hc = 0.0052 cm-1). Excellent agreement with the calculated IR spectrum identifies the 1,2,4-triazacyclohepta-1,2,4,6-tetraenes 20 (20a, 1969 cm -1; 20b, 1979 cm-1). Compounds 20 undergo photochemical ring-opening to 1-isocyano-3-diazopropenes 23. Further irradiation also causes Type II ring-opening of pyrimidinylnitrenes 19 to 2-(cyanimino)vinylnitrenes 21 (21a: D/hc = 0.875; E/hc = 0.00 cm-1), isomerization to cyaniminoketenimine 25 (2044 cm-1), and cyclization to 1-cyanopyrazoles 22. The reaction mechanisms are discussed and supported by DFT calculations on key intermediates and pathways. There is no evidence for the interconversion of 3-pyridazinylnitrenes 9 and 2-pyrimidinylnitrenes 19.
Synthesis and characterization of 2,4-pentadiynenitrile - A key compound in space science
Trolez, Yann,Guillemin, Jean-Claude
, p. 7224 - 7226 (2007/10/03)
(Chemical Equation Presented) Spaced out: Cyanobutadiyne (3) was synthesized in pure form from 1,3-butadiynyltributylstannane (1) and p-toluene-sulfonyl cyanide (2). Diyne 3 might be formed in the atmosphere of Titan or in the interstellar medium by photolysis of mixtures of acetylene and cyanoacetylene or dicyanoacetylene or of butadiyne and dicyanoacetylene. Only 1,6-addition is observed with nucleophiles.
Low temperature rate coefficients for the reactions of CN and C2H radicals with allene (CH2=C=CH2) and methyl acetylene (CH3CCH)
Carty, David,Le Page, Valery,Sims, Ian R.,Smith, Ian W.M.
, p. 310 - 316 (2007/10/03)
Using a continuous flow CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme or Reaction Kinetics in Uniform Supersonic Flow) apparatus, rate coefficients have been measured for the reactions of the cyanogen (CN) and ethynyl (C2H) radicals with allene (CH2=C=CH2) and methyl acetylene (CH3CCH) at temperatures from 295 down to 15 K for the reactions of CN and down to 63 K for those of C2H. All four reactions occur at rates close to the collision-determined limit. The results are compared with those obtained earlier for the reactions of other alkenes and alkynes, and, in the accompanying Letter by Vakhtin et al., with results for C2H+CH2=C=CH2 and C2H+CH3CCH obtained at 103 K using a pulsed Laval apparatus. The implications of these latest results for the chemistry of interstellar clouds and planetary atmospheres are discussed.
Process for production of 5-amino-3-methylpyrazole
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, (2008/06/13)
The process for producing 5-amino-3-methylpyrazole includes the steps of reacting 2,3-dichloropropene with a cyanogenating agent in the presence of a cuprous salt and water at a pH of 3-8 to obtain at least one intermediate selected from the group consisting of 3-chloro-3-butenonitrile and 2,3-butadienenitrile; reacting the at least one intermediate with a base in the presence of water at a pH of 12.5 or above to obtain 2-butynenitrile; and reacting the 2-butynenitrile with hydrazine. This process is advantageous in that it enables the production of 5-amino-3-methylpyrazole in high yield without using any reagent which may produce fire. 5-Amino-3-methylpyrazole is a useful intermediate for medicines, agricultural chemicals, photographic chemicals, etc.
A study on the scope of the photochemical ring contraction of substituted 2-amino-3-cyano-4H-pyrans to cyclobutenes: Crystal structure of 3-carbamoyl-3-cyano-1-ethoxycarbonyl-4-isopropyl-2-phenylcyclobutene
Armesto, Diego,Albert, Armando,Cano, Felix H.,Martin, Nazario,Ramos, Ana,Rodriguez, Miriam,Segura, Jose L.,Seoane, Carlos
, p. 3401 - 3405 (2007/10/03)
A study on the influence of substitution on the photochemical reactivity of a series of differently substituted 2-amino-4H-pyrans 10a-h has been carried out. All of the compounds undergo ring contraction to the corresponding cyclobutenes 11a-h on direct irradiation. Variable amounts of the enamides 12 and the alkynes 13 were also obtained, as secondary photoproducts. The results obtained show that the cyclization takes place in reasonable yields with alkyl, phenyl and hydrogen substitution at C-4 and at C-6. Cyano, ethoxycarbonyl and benzoyl substitution at C-5 also promotes the reaction. A high degree of stereochemical control was observed in most cases. The molecular geometry of cyclobutene 11a1 has been established by X-ray diffraction analysis. This study also shows that the crystal packing is formed by a system of chains linked by strong hydrogen bonds.
RAMFORD-STEVENS REACTION IN THE SERIES OF 1-ACYL-1-R-CYCLOPROPANES
Kuznetsova, T. S.,Kozhushkov, S. I.,Gromov, A. V.,Vatlina, L. P.,Kozlovskii, V. I.,Zefirov, N. S.
, p. 256 - 262 (2007/10/02)
Investigation of the relationships governing the carbene decomposition of the monotosylhydrazones of 1-R-1-acylcyclopropanes showed that ?-accepting substituents at the gem position to the carbonyl group increase the stability of the three-membered ring under the conditions of the Bamford-Stevens reaction.This leads to partial suppression of the cyclopropylmethyl-cyclobutene isomerization process and, as a result, to the formation of 1,1-gem-alkenylcyclopropanes and bicyclobutanes.
Production of Acrylonitrile and Other Unsaturated Nitriles from Alkenes and Alkynes
Henis, Neil B.,Miller, Larry L.
, p. 2526 - 2529 (2007/10/02)
Passage of unsaturated organic molecules trough a 13.56-MHz radio-frequency discharge, in the presence of cyanogen, results in the formation of unsaturated nitriles.Acrylonitrile was the major product from ethylene, propylene, acrolein, methyl vinyl ketone, or 1,1,1-trifluoropropylene. 1-Butene, 2-butene, and isobutylene gave mixtures of nitrile products with the CN situated at vinylic or allylic positions. 2-Butyne gave 1-cyanopropyne.Other compounds gave only low yields of nitriles and considerable polymer.The effects of power, pressure, flow rate, and ratios of reactants on the yields of acrylonitrile from propylene and cyanogen were studied.A typical power yield of acrylonitrile was 30 g kW-1 h-1.Maximum material yields of nitrile products were obtained at intermediate powers and pressures.The products are consistent with a reaction scheme involving attack of initially formed cyano radicals on the organic substrate.This step forms activated radical intermediates, which decay through elimination of an atom or group.The atom or group which is most weakly bound is preferentially lost.
Synthesis of Conjugated Alkynenitriles
Yalda, R,Rao, V. Subrahmanyeswara,Rao, Jampani Madhusundana
, p. 1046 - 1048 (2007/10/02)
The synthesis of 2-butynenitrile (7a), 3-(4-methoxyphenyl)-(7b)-, 3-(4-ethoxyphenyl)-(7c)-, 3-(4-nitrophenyl)-(7d)- and 3-(3,4,5-trimethoxyphenyl)-(7e)-propynenitriles by thermal decomposition of the corresponding acylcyanomethylenetriphenylphosphoranes (6a-e) is described.The ethoxycarbonylcyanomethylenetriphenylphosphorane (6f) under the same conditions does not give the alkynenitrile.Cleavage to triphenylphosphine oxide and acetylenic nitrile is the predominant fragmentation observed in the mass spectra of all the ylids.
