Electrolytic reduction of o-nitrobenzyl thiocyanate in buffered solutions on mercury

1985 ◽  
Vol 50 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Jaromír Hlavatý
Keyword(s):  
Acidic Medium ◽  
Reaction Path ◽  
Electrolytic Reduction ◽  
Buffer System ◽  
Height Ratio ◽  
Preparative Electrolysis ◽  
Clear Explanation ◽  
Ec Mechanism ◽  
Controlled Potential

The o-nitrobenzyl thiocyanate (I) behaves differently on the DME and on a large mercury pool electrode. Polarography did not give a sufficiently clear explanation of the reaction mechanism, only the preparative experiments yielded useful results. Whereas polarographic curves in solutions of Britton-Robinson buffer system with 50% by vol. ethanol exhibit two cathodic waves within the pH region 1-12, corresponding according to their height ratio to an uptake of 4 e and 2 e respectively, the controlled potential preparation electrolysis (CPE) and coulometry results indicate a more complicated reaction path. In the CPE carried out at the concentration of I 1 . 10 -2 mol/l the electroreductive splitting of CH2-SCN occurs as the first step. Nitrobenzyl radicals so formed react in the follow-up dimerization resulting in dibenzyl or toluene structures. Simultaneously or at a later stage the completion of the electrolytic reduction of the nitro group proceeds to the hydroxylamino group. In solution of 9 > pH > 1 the CPE of nitro compound I takes place by an ECEC mechanism yielding dibenzodiazocine III, its N-oxide IV and 2,2'-dimethylazoxybenzene (V). In course of preparative electrolysis in strongly acidic medium 2-amino-benzo(l,3)-thiazine-l-oxide (II) is formed by an EC mechanism.

scholarly journals Cement bridging phenomenon in percutaneous vertebroplasty for adjacent vertebral compression fracture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yun-Da Li ◽  
Tsung-Ting Tsai ◽  
Chi-Chien Niu ◽  
Po-Liang Lai
Keyword(s):  
Vertebral Compression Fracture ◽  
Body Height ◽  
Compression Fracture ◽  
Plain Film ◽  
Imaging Features ◽  
Height Ratio ◽  
Kyphotic Angle ◽  
Anterior Body ◽  
New Onset

AbstractIn some cases of vertebroplasty for adjacent fractures, we observed a cement bridging phenomenon, in which the injected cement flowed from the newly fractured vertebra to the previously cement-augmented vertebra through the space between the abutting anterior longitudinal ligament and the vertebral column. The purpose of this retrospective study was to investigate this phenomenon. From January 2012 to December 2014, patients who sustained new-onset adjacent vertebral compression fracture and who were again treated with vertebroplasty were enrolled. We divided the patients into two groups, the bridging group and the nonbridging group, to analyze the difference between them. Results showed that the cement bridging phenomenon occurred in 18 (22.8%) of the 79 patients. Significant differences between the bridging and nonbridging groups were identified in the following 3 imaging features: severe loss of the anterior vertebral body height at the new-onset adjacent vertebra on plain film (odds ratio [OR] = 4.46, p = 0.014), fluid accumulation (OR = 36.27, p < 0.001) and hypointense signaling (OR = 15.67, p < 0.001) around the space anterior to the abutting vertebral bodies and the corresponding intervertebral disc on MRI. After a 2-year follow-up, both the mean value of the focal kyphotic angle and anterior body height ratio were significantly better in the cement bridging group than in the nonbridging group. The cement bridging phenomenon, which has never been reported in the literature, is not rare in clinical practice. This phenomenon was associated with better maintenance of focal kyphotic angle and anterior body height ratio during the 2-year follow-up.

scholarly journals Follow-up results of microendoscopic discectomy compared to day surgery using percutaneous endoscopic lumbar discectomy for the treatment of lumbar disc herniation

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhaojun Song ◽  
Maobo Ran ◽  
Juan Luo ◽  
Kai Zhang ◽  
Yongjie Ye ◽  
...  
Keyword(s):  
Back Pain ◽  
Blood Loss ◽  
Lumbar Disc ◽  
Postoperative Recurrence ◽  
Day Surgery ◽  
Lumbar Discectomy ◽  
Height Ratio ◽  
Microendoscopic Discectomy ◽  
Endoscopic Lumbar Discectomy

Abstract Background Percutaneous endoscopic lumbar discectomy (PELD) is satisfactory for hospitalized patients with lumbar disc herniation (LDH). Currently, only a few studies have reported about the day surgery patients undergoing PELD. Methods A total of 267 patients with LDH underwent PELD during day surgery and were followed up for at least 3 years. Clinical outcomes were assessed using the visual analog scale (VAS) for leg and lower back pain (VAS-B and VAS-L, respectively) and the Oswestry disability index (ODI). The radiological outcomes, such as lumbar lordosis (LL), sacral slope (SS), the disc-height ratio, and disc instability, were recorded and compared. The clinical effects between patients treated by PELD during day surgery and microendoscopic discectomy (MED) for contemporaneous hospitalized 116 patients with LDH were compared. Results Patients treated by PELD had lower blood loss and shorter hospital stay (P <  0.001) compared to those treated by MED. VAS-L, VAS-B, and ODI decreased significantly after PELD than before the operation and 3 years postoperatively. The postoperative VAS-B in the PELD group was significantly decreased than in the MED group (P = 0.001). The complications rate was 9.4% in the PELD group and 12.1% in the MED group (P = 0.471). The 1-year postoperative recurrence rate in the PELD group was much higher than that in MED group (P = 0.042). The postoperative LL and SS in the PELD group improved significantly compared to the values in the MED group (P <  0.001). According to the disc-height ratio at 3-year follow-up, a significant height loss was observed in the MED group than in the PELD group (P = 0.014). Conclusions Although the 1-year postoperative recurrence rate was relatively high, the day surgery for LDH undergoing PELD had advantages in terms of less blood loss intraoperatively, short hospital stay, efficacy for back pain, and efficiency to maintain lumbar physiological curvature.

scholarly journals Réduction électrochimique de 4H-1,3-thiazines: obtention de 6H-1,3-thiazines et (ou) de pyrroles substitués

1992 ◽  
Vol 70 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Abdesselam Abouelfida ◽  
Jean Paul Pradère ◽  
Michel Jubault ◽  
André Tallec
Keyword(s):  
Acidic Medium ◽  
Acetate Buffer ◽  
Buffer Medium ◽  
Mercury Cathode ◽  
Controlled Potential

Controlled potential electroreduction (protic medium, mercury cathode) of substituted 2-ethoxy and 2-phenyl-4H-1,3-thiazines leads to 6H-1,3-thiazines and (or) pyrroles. The nature of the isolated products appears strongly dependent on pH of the medium and type of substitution: pyrrole formation takes place in acidic medium (0.5 mol L−1 H2SO4) and is favoured by phenyl and alkoxycarbonyl groups at positions 2 and 4, respectively; formation of 6H-1,3-thiazines and their reduction products (substituted thiobenzamides, carbamates and 2-thiazoline) occurs in weakly acidic (acetate buffer) or basic (ammoniacal buffer) medium. Keywords: electrochemical reductions, substituted 4H- and 6H-1,3-thiazines, pyrroles, 2-thiazoline, cyclic regression.

scholarly journals Al-Qur’an dan Relasi Antar Umat Beragama; Diskursus Tentang Pendidikan Pluralisme Agama di Indonesia

2018 ◽  
Vol 5 (3) ◽  
pp. 241-254
Author(s):  
Kamarusdiana Kamarusdiana
Keyword(s):  
Social Context ◽  
Religious Pluralism ◽  
Religious Groups ◽  
Social Fact ◽  
Clear Explanation ◽  
The Stability ◽  
The Right ◽  
Islamic Values ◽  
Education Process

Abstract:The issue of diversity in religion is a social fact that has continued to experience conflict shocks lately. Not without reason, the conflict occurred on the grounds of sentiment towards other religions. This has an impact on the disruption of the stability of relations between religious groups. The discourse of religious pluralism is an alternative in overcoming this problem. Grounding religious pluralism is the right effort by not injuring religious values. Islam actually provides a clear explanation in the Koran about building a tolerant relationship in religion. This article will explain and provide an explanation of Islamic values in the Qur'an as an effort to develop religious pluralism that needs to be represented in a plural social context. It is hoped that with this, the harmony between religious people will be realized. Besides that, as a concrete follow-up, an education process is needed about the importance of tolerance in religion.Keywords: Qur'an, Tolerance, Religious Pluralism, Harmony AbstrakIsu keberagaman dalam beragama menjadi fakta sosial yang terus mengalami guncangan konflik belakangan ini. Bukan tanpa alasan, konflik tersebut terjadidengan alasan sentimen terhadap agama lain. Hal ini berdampak pada terganggunya stabilitas hubungan antar umat beragama. Wacana pluralisme agama menjadi alternatif dalam mengatasi masalah tersebut. Membumikan pluralisme agama merupakan upaya yang tepat dengan tidak menciderai nilai-nilai agama. Islam sejatinya hadir memberikan penjelasan yang gamblang didalam Alquran tentang membangun hubungan yang toleran dalam beragama. Tulisan ini akan memaparkan sekaligus memberikan penjelasan nilai-nilai keislaman yang ada dalam Alquran sebagai upaya mengembangkan pluralisme agama yang perlu direpresentasikan dalam konteks sosial yang plural. Diharapkan dengannya, akan terwujud kerukunan antar umat beragama.Selain itu, sebagai tindak lanjut yang konkrit dibutuhkan proses edukasi tentang pentingnya toleransi dalam beragama.  Kata Kunci: Alquran, Toleransi, Pluralisme Agama, Kerukunan

The Application of 1,2-Oxazinanes as Chiral Cyclic Weinreb Amide-type Auxiliaries Leading to a Three Component One-Pot Reaction

Synthesis ◽  
2021 ◽  
Author(s):  
Gerhard Hilt ◽  
Ludmila Hermann ◽  
Jan Fährmann
Keyword(s):  
Reaction Path ◽  
Organometallic Compounds ◽  
Alder Reaction ◽  
Diels Alder ◽  
Chiral Auxiliary ◽  
One Pot ◽  
Weinreb Amide ◽  
Diels Alder Reaction ◽  
The Stability

1,2-Oxazines were synthesised via a copper-catalysed aerobic acyl nitroso Diels-Alder reaction from 1,4-disubstituted 1,3-dienes and N-Boc-hydroxylamine. From this, 1,2-oxazinanes were received in a novel follow-up reaction path. The stability of several 1,2-oxazines and 1,2-oxazinanes towards organometallic compounds was tested to rate their operability as cyclic chiral Weinreb amide auxiliaries. 3,6-Di-tert-butyl-1,2-oxazinane gave the best results and was introduced as chiral Weinreb amide-type auxiliary to yield chiral α-substituted ketones in a diastereomeric ratio of up to 98:2. The removal of the auxiliary can be performed with BuLi to form unsymmetrical α-chiral ketones. Thereafter, the chiral auxiliary can be re-isolated and purified by sublimation in vacuum.

Electrochemical reduction of nickel(II) dithiocarboxylates at the mercury electrode

1997 ◽  
Vol 75 (7) ◽  
pp. 1023-1029 ◽  
Author(s):  
A. Safavi ◽  
L. Fotouhi
Keyword(s):  
Electron Transfer ◽  
Electrochemical Techniques ◽  
Mercury Electrode ◽  
Electrode Reaction ◽  
Ece Mechanism ◽  
Reduction Mechanisms ◽  
Ec Mechanism ◽  
Controlled Potential ◽  
Electron Reduction ◽  
Derivatives Of

The reduction mechanisms of a series of nickel(II) dithiocarboxylate complexes have been investigated in dimethyl sulphoxide at the mercury electrode. Various electrochemical techniques, including polarography, cyclic voltammetry, chronoamperometry, and controlled potential coulometry, were employed. The reduction of the complexes of the acid derivatives of 2-aminocyclopentene-1-dithiocarboxylate (ACD) proceeds initially by an ECE mechanism (electron transfer – chemical reaction – electron transfer) followed by a one-electron irreversible process. The nature of the complete electrode reaction suggests a metal-centered reduction. The nickel complexes of the ester derivatives of ACD underwent a one-electron reduction that was subject to a follow-up catalytic reaction (EC′ mechanism) and the original complex is regenerated through this regeneration reaction. Keywords: reduction, nickel(II) dithiocarboxylate, mercury electrode.

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