THE REACTION OF CYANOGEN WITH 1,3-BUTADIENE

1947 ◽  
Vol 25b (3) ◽  
pp. 272-282 ◽  
Author(s):  
G. J. Janz ◽  
R. G. Ascah ◽  
A. G. Keenan
Keyword(s):  
Atmospheric Pressure ◽  
Main Product ◽  
Vapour Phase ◽  
Diels Alder ◽  
Diene Synthesis ◽  
Ether Solution ◽  
First Time

Cyanogen and butadiene have been found to react. The main product of the reaction was identified as 2-cyanopyridine. Some 2,2′-dipyridyl and a number of unidentified compounds were also found present in the product in small yields. No evidence for the presence of β-hydromucononitrile could be found. The reaction has been studied at atmospheric pressure in the vapour phase, and in ether solution, and at superatmospheric pressures in steel or glass bombs. In all cases the course of the reaction was essentially the same, 2-cyanopyridine being the main product. The formation of 2-cyanopyridine from butadiene and cyanogen is formulated as a Diels–Alder synthesis, in which the primary adduct undergoes a dehydrogenation to yield the final product. This is the first time to our knowledge that cyanogen has been reported as a dienophile in the diene synthesis.

scholarly journals Observations of X-rays from Laboratory Sparks in Air at Atmospheric Pressure under Negative Switching Impulse Voltages

Atmosphere ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 169 ◽  
Author(s):  
Mahbubur Rahman ◽  
Pasan Hettiarachchi ◽  
Vernon Cooray ◽  
Joseph Dwyer ◽  
Vladimir Rakov ◽  
...  
Keyword(s):  
Rise Time ◽  
Atmospheric Pressure ◽  
Opposite Polarity ◽  
X Rays ◽  
X Ray ◽  
Impulse Voltage ◽  
First Time ◽  
Switching Impulses ◽  
Low Rate

We present observations of X-rays from laboratory sparks created in the air at atmospheric pressure by applying an impulse voltage with long (250 µs) rise-time. X-ray production in 35 and 46 cm gaps for three different electrode configurations was studied. The results demonstrate, for the first time, the production of X-rays in gaps subjected to switching impulses. The low rate of rise of the voltage in switching impulses does not significantly reduce the production of X-rays. Additionally, the timing of the X-ray occurrence suggests the possibility that the mechanism of X-ray production by sparks is related to the collision of streamers of opposite polarity.

Kinetic Study of the Diels-Alder Reaction of Cyclopentadiene with Bis(2-Ethylhexyl) Maleate

2013 ◽  
Vol 634-638 ◽  
pp. 541-545 ◽  
Author(s):  
Jun Seong Park ◽  
Dae Hee Yun ◽  
Tae Won Ko ◽  
Yong Sung Park ◽  
Je Wan Woo
Keyword(s):  
Kinetic Study ◽  
Reaction Temperature ◽  
Atmospheric Pressure ◽  
Arrhenius Equation ◽  
Alder Reaction ◽  
Diels Alder ◽  
Influence Of Temperature ◽  
Diels Alder Reaction ◽  
Influence Of Temperature On ◽  
Kinetics Of

The kinetics of the Diels-Alder reaction of cyclopentadiene with bis(2-ethylhexyl) maleate has been studied at temperatures between 25 and 100 °C and at atmospheric pressure. The influence of temperature on the kinetic constants was determined by fitting the results to the Arrhenius equation. As a result, fitting line similar with the linear curve of the Arrhenius equation at 25, 30 and 40 °C. However, the fitting curve, at 60, 80 and 100 °C, tended towards the outside of the curve in the form of Arrhenius equation. The ratio of endo/exo was a slight change from increase of the reaction temperature.

CO2 hydrogenation into CH4 over Ni–Fe catalysts

2018 ◽  
Vol 11 (03) ◽  
pp. 1850057 ◽  
Author(s):  
Reza Meshkini Far ◽  
Olena V. Ischenko ◽  
Alla G. Dyachenko ◽  
Oleksandr Bieda ◽  
Snezhana V. Gaidai ◽  
...  
Keyword(s):  
Low Temperature ◽  
Synergistic Effect ◽  
Atmospheric Pressure ◽  
High Efficiency ◽  
Co2 Hydrogenation ◽  
Hydrogenation Catalysts ◽  
Fe Catalysts ◽  
First Time ◽  
Supported Ni ◽  
Hydrogenation Of Co

Here, we report, for the first time, on the catalytic hydrogenation of CO2 to methane at atmospheric pressure. For the preparation of hydrogenation catalysts based on Ni and Fe metals, a convenient method is developed. According to this method, low-temperature reduction of the co-precipitated Ni and Fe oxides with hydrogen gives the effective and selective bimetallic Ni[Formula: see text]Fe[Formula: see text], Ni[Formula: see text]Fe[Formula: see text] and Ni[Formula: see text]Fe[Formula: see text] catalysts. At the temperature range of 300–400[Formula: see text]C, they exhibit a high efficiency of CH4 production with respect to monometallic Ni and Fe catalysts. The results imply a synergistic effect between Ni and Fe which caused the superior activity of the Ni[Formula: see text]Fe[Formula: see text] catalyst conversing [Formula: see text]% of CO2 into CH4 at 350[Formula: see text]C. To adapt the Ni–Fe catalysts in the industry, the effect of two different carriers on the efficiency of the alumina-supported Ni[Formula: see text]Fe[Formula: see text] catalyst was investigated. It is found that the Ni[Formula: see text]Fe[Formula: see text]/[Formula: see text]-Al2O3 catalyst effectively conversed CO2 giving 100% methane yield already at 275[Formula: see text]C.

scholarly journals Direct observation of o-benzyne formation in photochemical hexadehydro-Diels–Alder (hν-HDDA) reactions

2020 ◽  
Vol 11 (34) ◽  
pp. 9198-9208 ◽  
Author(s):  
Xiaonan Ma ◽  
Jan Maier ◽  
Michael Wenzel ◽  
Alexandra Friedrich ◽  
Andreas Steffen ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Direct Observation ◽  
Diels Alder ◽  
Visible Absorption Spectrum ◽  
Visible Absorption ◽  
First Time

We report the transient ultraviolet/visible absorption spectrum of an o-benzyne species in solution for the first time.

scholarly journals Acylation derivatization based LC-MS analysis of 25-hydroxyvitamin D from finger-prick blood

2019 ◽  
Vol 60 (5) ◽  
pp. 1058-1064 ◽  
Author(s):  
Juan Le ◽  
Teng-Fei Yuan ◽  
Jia-Qing Geng ◽  
Shao-Ting Wang ◽  
Yan Li ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Supplementation ◽  
Diels Alder ◽  
Clinical Value ◽  
Hydroxyvitamin D ◽  
Optimal Outcomes ◽  
Finger Prick ◽  
25 Hydroxyvitamin D ◽  
Novel Strategy ◽  
First Time

Vitamin D metabolite analysis possessed significant clinical value for the pediatric department. However, invasive venipuncture sampling and high blood consumption inflicted much suffering on patients. For alleviation, we carried out a LC-MS method for 25-hydroxyvitamin D quantification in only 3 μl of plasma from the considerably less invasive finger-prick blood samples. To improve sensitivity, acylation on C3-hydroxyl (by isonicotinoyl chloride) rather than Diels-Alder adduction on s-cis-diene structure was for the very first time introduced into vitamin D metabolite derivatization. Compared with the existing derivatization approaches, this novel strategy not only prevented isomer interference, but also exhibited higher reacting throughput. For certification, the methodology was systematically validated and showed satisfying consistency with SRM927a. During clinical application, we found a convincing correlation between 25-hydroxyvitamin D and indirect/total bilirubin in jaundiced newborns. Such an observation indicated that vitamin D supplementation may help to achieve optimal outcomes in neonatal jaundice.

Ring-Closing Metathesis Approach to Cage Propellanes Containing Oxepane and Tetrahydrofuran Hybrid System

Synthesis ◽  
2017 ◽  
Vol 49 (24) ◽  
pp. 5339-5350 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Subba Cheekatla ◽  
Darshan Mhatre
Keyword(s):  
Claisen Rearrangement ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ring Closing Metathesis ◽  
Cage Compounds ◽  
Transannular Cyclization ◽  
Diels Alder Reaction ◽  
Grignard Addition ◽  
Key Steps ◽  
First Time

The preparation of a variety of structurally interesting oxygenated cage compounds involving atom-economic processes such as Claisen rearrangement, Diels–Alder reaction, [2+2] photocycloaddition, and ring-closing metathesis (RCM) as key steps is reported. For the first time, oxepane ring system is introduced in cage framework using olefin metathesis as a key step. These cage systems assembled here are difficult to prepare by traditional methods. The synthetic sequence described here opens up new routes to higher order polycycles containing heteroatoms without the involvement of protecting groups. Transannular cyclization observed during Grignard addition and the RCM protocol used here may be applicable to generate unknown oxygenated cage systems.

Stationary flames of methyl nitrate and methyl nitrite

1955 ◽  
Vol 232 (1190) ◽  
pp. 389-403 ◽  
Keyword(s):  
Nitric Oxide ◽  
Atmospheric Pressure ◽  
Burning Velocity ◽  
Vapour Phase ◽  
Main Reaction ◽  
Methyl Nitrite ◽  
Nitrate Esters ◽  
Methyl Nitrate ◽  
Low Pressures ◽  
Ethyl Nitrite

Methyl nitrate (CH 3 ONO 2 ) is the most explosive of the nitrate esters, and previous studies have been confined mainly to the slow thermal decomposition, and to the vapour phase explosion at low pressures in closed vessels. A stationary decomposition flame has now been maintained and studied spectrographically. A t low pressures the zones of reaction are clearly separated. From the early stages of the flame strong formaldehyde bands are emitted. This decomposition flame has been successfully simulated in artificial mixtures of methyl nitrite with oxygen. The results obtained are in accord with the preliminary fission of the nitrate molecule in the pre-heat zone of the flame: CH 3 ONO 2 →CH 3 O + NO 2 . The combustion flame of m ethyl nitrate with oxygen, nitric oxide and nitrogen dioxide has also been examined at low pressures. At atmospheric pressure, m ethyl nitrite (CH 3 ONO) has been found to support a decomposition flame of very small burning velocity. However, the combustion of m ethyl nitrite with oxygen at atmospheric pressure is an extremely fast and vigorous flame. It has been observed in both pre-mixed and diffusion systems and information about the changes occurring in it have been obtained by absorption and emission spectroscopy. All the experimental results may be interpreted in terms of two general principles: the reluctance of nitric oxide to react except at high temperatures and pressures and the frequent occurrence in flames of extensive pyrolytic reactions before the main reaction zone is reached.

A computational view on vapour phase coagulation of nanoparticles synthesized by atmospheric pressure PECVD

2015 ◽  
Vol 12 (7) ◽  
pp. 891-903 ◽  
Author(s):  
Maxim V. Mishin ◽  
Kirill Y. Zamotin ◽  
Vera S. Protopopova ◽  
Andrey A. Uvarov ◽  
Leonid A. Filatov ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Phase

Horizontal Moisture Transport Dominates the Regional Moistening Patterns in the Arctic

2020 ◽  
Vol 33 (16) ◽  
pp. 6793-6807
Author(s):  
Tiina Nygård ◽  
Tuomas Naakka ◽  
Timo Vihma
Keyword(s):  
Sea Ice ◽  
Atmospheric Pressure ◽  
Moisture Transport ◽  
Reanalysis Data ◽  
The Arctic ◽  
Surface Evaporation ◽  
Open Sea ◽  
Sea Ice Decline ◽  
First Time ◽  
Limited Period

AbstractAlong with the amplified warming and dramatic sea ice decline, the Arctic has experienced regionally and seasonally variable moistening of the atmosphere. Based on reanalysis data, this study demonstrates that the regional moistening patterns during the last four decades, 1979–2018, were predominantly shaped by the strong trends in horizontal moisture transport. Our results suggest that the trends in moisture transport were largely driven by changes in atmospheric circulation. Trends in evaporation in the Arctic had a smaller role in shaping the moistening patterns. Both horizontal moisture transport and local evaporation have been affected by the diminishing sea ice cover during the cold seasons from autumn to spring. Increases in evaporation have been restricted to the vicinity of the sea ice margin over a limited period during the local sea ice decline. For the first time we demonstrate that, after the sea ice has disappeared from a region, evaporation over the open sea has had negative trends due to the effect of horizontal moisture transport to suppress evaporation. Near the sea ice margin, the trends in moisture transport and evaporation and the cloud response to those have been circulation dependent. The future moisture and cloud distributions in the Arctic are expected to respond to changes in atmospheric pressure patterns; circulation and moisture transport will also control where and when efficient surface evaporation can occur.

Microwave-assisted Diels-Alder synthesis

2001 ◽  
Vol 79 (12) ◽  
pp. 1906-1909 ◽  
Author(s):  
Christopher K Jankowski ◽  
Gaëtan LeClair ◽  
Jacqueline MR Bélanger ◽  
Jocelyn RJ Paré ◽  
Marie-Rose VanCalsteren
Keyword(s):  
High Resolution ◽  
Microwave Synthesis ◽  
Alder Reaction ◽  
Diels Alder ◽  
Microwave Method ◽  
Diene Synthesis ◽  
Microwave Assisted ◽  
Diels Alder Reaction ◽  
Pyridine Carboxylate ◽  
Danishefsky's Diene

The synthesis of isoquinolinone carboxylates was performed using arecoline or its isomer N-methyl tetrahydro pyridine carboxylate with Danishefsky's diene via thermal or microwave assisted Diels-Alder reaction. The comparison of both condensation modes showed that the microwave method not only afforded higher yields of the adducts, but also lead to the formation of a new α,β-unsaturated pyridyl ketone. All structures were identified with the help of high resolution 2D NMR.Key words: Diels-Alder microwave assisted reaction, microwave synthesis, Michael, diene, isoquinoline carboxylate synthesis, Danishefsky diene synthesis, MAP Diels-Alder2.

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