Synthesis and Characterization of Some Transition Metal Chelates of 5-(1-Hydroxy-6-Naphthylazo-3-Sodium Sulphonate) Thiobarbituric (L_1) and Barbituric (L_2) Acids

Some transition metal chelates of two ligands L1 and L2 were prepared and characterized by elemental analysis. The IR and 1H NMR spectra of several chelates of two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metaI ions, in most of the studied chelates, and that the two ligands L1 and L2 showed the involvement of the azo group in chelation with the transition metal ions, in most of the studied chelates, and that the two ligands L1 and L2 were coordinated either in the enol or the keto form. IR spetra also showed that Fe(III)-, Ni(II)-, Mn(II)-, VO(II)-L1 and Cu(II)-L2 chelates behaved in a bidentate manner, in contrast with the two (1:1) M:L cobalt chelates with the two ligands are tridentate.TG analysis indicated the presence of three to twelve water molecules of hydration eliminated on heating up to 150℃ and one or two coordinated water molecules removed at 150~180℃.The octahedral structure is proposed fOr all the chelates, except Cu(II)-L2 and Ni(II)-L1 chelates which have square planar geometry, based on their electronic spectra

Effect of Cross-linking Agent on Barbituric Acid-initiated Resin

To improve the tensile bond strength of denim bonding agents, the adhesion between denim and MMA resin was investigated by applying initiator systems containing 1-cyclohexyl-5-ethyl barbituric acid (CEB), copper acetyl acetonate (CAA), quaternary ammonium chloride (QAC). cupric ion, with the addition of TEGDMA, an.d pretreatment solution for denim, and an HEMA primer. The effects of a cross-linking agent on barbituric acid-initiated denim bonding resin were examined by measuring degree of conversion, molecular weight, hardness of bonding resin, and tensile bond strengths.

Knoevenagel condensation of α,β-unsaturated aromatic aldehydes with barbituric acid under non-catalytic and solvent-free conditions

An efficient route for the synthesis of 5-（arylpropenylidine）-2,4,6-pyrimidinetrione 3 from an appropriate α,βunsaturated aromatic aldehydes 1 and barbituric acid 2 under both non-catalytic and solvent-free microwave irradiation conditions was described. In this way, a range of biologically important compounds 3 was obtained in good to excellent yields （86-98%） in a very short reaction time （30-80 s）.

Effect of Frontier Orbital on Aggregation Behavior of Barbituric Acid Derivatives

Two amphiphilic barbituric acid derivatives with a D-π-A structure, 5-(4-dodecyloxybenzylidene)-(1H,3H)-2,4,6-pyrimidinetrione(PB_ 12) and 5-(4-N,N-didodecylaminobenzylidene)-(1H,3H)-2,4,6-pyrimidintrione(AB_ 12) were found to show different aggregation behavior in chloroform. PB_ 12, a derivative with weak electron donating and strong electron drawing substituents, tends to aggregate in a head-to-tail manner, whereas AB_ 12, a derivative with both strong electron donating and drawing substituents, tends to aggregate in a face-to-face manner at a higher concentration. The cyclic voltammograms of AB_ 12 and PB_ 12 show that their energy levels of LUMO approach each other, however, the energy level of HOMO of AB_ 12 is much higher than that of PB_ 12.

Molecular diversity of triphenylphosphine promoted reaction of electron-deficient alkynes and arylidene Meldrum acid(N,N’-dimethylbarbituric acid)

The three-component reaction of triphenylphosphine,dimethyl hex-2-en-4-ynedioate and arylidene N,N’-dimethylbarbituric acids in dry methylene dichloride at room temperature afforded trans-1,3-disubstituted 7,9-diazaspiro[4.5]dec-1-enes in good yields and with high diastereoselectivity.However,the similar three-component reaction with arylidene Meldrum acids resulted in a mixtures of cis/trans-1,2-disubstituted 7,9-dioxaspiro[4.5]dec-1-enes.Additionally,the three-component reaction of triphenylphosphine,dimethyl but-2-ynedioate and arylidene Meldrum acids gave polysubstituted 5-(triphe nyl-λ~5-phosphanylidene)cyclopenta-1,3-die nes.A plausible reaction mechanism was proposed for the formation of various products with different regioselectivity and diastereoselectivity.

One-pot synthesis of 7-aryl-11,12-dihydrobenzo[h]pyrimido-[4,5-b]quinoline-8,10(7H,9H)-diones via three-component reaction in ionic liquid

A series of new 7-aryl-11,12-dihydrobenzo[h]pyrimido-[4,5-b]quinoline-8,10（7H,9H）-diones were synthesized via three-component reaction of aldehydes,l-naphthylamine and barbituric acid in ionic liquid.The method provided several advantages such as easy work-up,high yields and environmentally benign procedure.

铁酸钴纳米粒子:室温下点击合成亚芳基巴比妥酸衍生物的高效可磁性分离多相催化剂(英文)

A coprecipitation method was used to synthesize superparamagnetic CoFe2O4 nanoparticles without using any capping agents/surfactants. The prepared nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, a vibrating sample magnetometer (VSM), N2 adsorption and thermogravimetric/differential thermal analysis/differential thermal gravimetry techniques. The synthesized spinel CoFe2O4 nanoparticles had an average size of 2-8 nm with a high surface area (140.9 m2/g). The field-dependent magnetization, demonstrated by VSM and saturation magnetization, was found to be 1.77 emu/g. An efficient method was used for the synthesis of arylidene barbituric acid derivatives using CoFe2O4 magnetic nanoparticles as a magnetically separable and reusable catalyst in aqueous ethanol. The attractive features of this synthetic protocol were very short reaction time, high yields, high turnover frequency, simple work-up procedure, economy, a clean reaction methodology, and chemoselectivity, as well as provision of an ecofriendly and green synthesis.

Molecular Component Structures MediatedFormation of Self-assemblies

Molecular recognition directed self-assemblies from complementary molecular components, melamine and barbituric acid derivatives were studied by means of NMR, fluorescence, and TEM. It was found that both the process of the self-assembly and the morphologies of the result- ed self-assemblies could be mediated by modifying the structures of the molecular components used. The effect of the structures of the molecular components on the formation of the self-as- semblies was discussed in terms of intermolecular interactions.

STUDY OF COMPLEXATION OF BARBITURATES WITH β-CYCLODEXTRIN

The nature of the quenching of barbiturate fluorescence by forming inclusion complexcs with β-cyclodextrin is investigated principally using fluorescence/absorption and Fourier transform infrared(FTIR)spectroscopy.The relatively weak complexes formed in aqueous solutions indicated through the IR spectroscopies are confirmed by the apparent formation constants acquired by using fluorescence method.Further specific information concerning the mechanisms of interaction has been ex- plored in detail by means of the analysis of the electrochemical and spectroscopic behaviour.

Delayed post-hypoxic leukoencephalopathy following barbiturate overdose: A case report

Rationale:Delayed post-hypoxic leukoencephalopathy(DPHL)is usually an overlooked condition,which arises as a result of a multitude of reversible and irreversible conditions.Patient’s Concern:A 50-year-old female with a history of epilepsy,who developed DPHL 12 days after respiratory failure secondary to barbiturate toxicity.Diagnosis:DPHL on magnetic resonance imaging of the brain.Interventions:Mechanical ventilation was initiated for respiratory failure and hemodialysis for barbiturate toxicity.Outcomes:The patient developed akinetic mutism due to infirmity and had a residual disability,which led to permanent dependency.Lessons:The diagnosis of DPHL is often delayed or missed,given the rarity of this condition and its inconsistent clinical symptomatology.Diagnostic delay can be avoided by early recognition of the classical“delayed onset”symptoms.

Bucolome N-Glucuronide Formation: Species Differences and Identification of Human UDP-Glucuronosyltransferase Isoforms

The barbituric acid derivative bucolome (BCP) is a nonsteroidal anti-inflammatory drug. The present study investigated whether BCP N-glucuronide (BCP-NG, the primary metabolite of BCP) was produced in mammalian species other than rats, and attempted to identify the UDP-glucuronosyltransferase (UGT) isoform (s) responsible for formation of BCP-NG in humans. BCP-NG was detected in all species tested. The results were as follows (pmol equivalent/ min/mg protein): rat, 479 ± 83;Mongolian gerbil, 378 ± 9;rabbit, 275 ±26;guinea pig, 257 ± 10;human, 242 ± 18;hamster, 177 ± 22;and mouse, 167 ± 15. Since human liver microsomes formed BCP-NG, we investigated the metabolites of BCP excreted in the urine of a patient after oral administration of BCP (600 mg). BCP and BCP-NG were excreted in the urine at amounts of 2.9 mg (about 0.5% of the dose) and 14.4 mg (about 2.5% of the dose) over 12 hours. In order to identify the UGT isoforms involved in formation of BCP-NG in humans, we investigated BCP-NG formation by the microsomes of insect cells expressing each of twelve UGT isoforms (hUGT1A1, 1A3, 1A4, 1A6, 1A7, 1A8, 1A9, 1A10, 2B4, 2B7, 2B15, and 2B17). As a result, BCP-NG formation (pmol equivalents/min/mg protein) was observed with microsomes expressing hUGT1A1 (142), 1A3 (196), 1A4 (8), 1A7 (8), 1A8 (66), 1A9 (38), 1A10 (9), 2B4 (7) and 2B7 (16). In particular, the activity of hUGT1A1 and 1A3 was high. These results suggest that the UGT isoforms responsible for formation of BCP-NG exist in various mammalian species, including humans, and that the UGT 1A family is primarily responsible for BCP N-glucuronide formation in humans.

Barbiturate Coma: Rebound and Refractory Hyperkalemia

Purpose: To describe a traumatic brain injury patient who experienced profound dyskalemia upon the initiation and cessation of a pentobarbital infusion and propose management options for future patients receiving this intervention. Methods: Case report. Results: Case report. Conclusions: Dyskalemia has become an anticipated side effect of high dose barbiturate infusions in the setting of elevated intracranial pressure. Hypokalemia during the administration of a barbiturate infusion has been identified within this patient population and was an expected adverse event during this intervention. However, in this case we observed a significant and complicated refractory hyperkalemia upon cessation of the barbiturate infusion which required aggressive management. An objective causality assessment suggests that this adverse event was possibly related to pentobarbital. What this case documents that other cases have not is that upon re-introduction of the pentobarbital infusion, serum potassium levels did not normalize. This questions whether severe rebound hyperkalemia is a pharmacodynamic or infusion-related reaction. More data is needed to identify the mechanism of this adverse event and recommend an appropriate treatment approach.

Novel Synthesis of Barbiturates

Knovenagel reaction of barbituric acid with different aldehydes were used to synthesize new barbiturates. This is a novel method which can be used to synthsis various types of new generation of barbiturates which are different from the previously reported.

Alum （KAI（SO4）2·12H2O） Catalyzed Multicomponent Transformation： Simple, Efficient, and Green Route to Synthesis of Functional- ized Spiro[chromeno[2,3-d]pyrimidine-5,3＇-indoline]-tetraones in Ionic Liquid Media

The combination of isatin, barbituric acid, and cyclohexane-1,3-dione derivatives in the presence of alum （KAI（SO4）2· 12H2O） as a catalyst for 15 min was found to be a suitable and efficient method for the synthesis of spiro[chromeno[2,3-d]pyrimidine-5,3＇-indoline]-tetraones.

Recognition-improved monolayer formation on air-water interface

Molecular recognition mechanism was introduced into the monolayer formation of two barbituric derivatives, B1 and B2, on a series of melamine derivatives containing water subphase. The recognition pattern was found that each barbituric(or melamine) group forms 9-fold H-bonds on its two edges, respectively, with two of its neighboring melamine(barbituric) cores in the ratio of 1:1 on air-water interface. The area per molecule in this pattern is about 60-65 Angstrom(2) for both B1 and B2. Such recognition improves the monolayer formation of B1 by increasing the collapse pressure around 20 mN/M and modulates the intermolecular distance of B2 in monolayer. These effects should be quite meaningful for both theoretical research and practical application of Langmuir-Blodgett films, especially.

Improved microwave-assisted catalyst-free synthesis of9-aryl-5,9-dihydropyrimido[4,5-d][1,2,4]triazolo[1,5-a]pyrimidine-6,8(4H,7H)-dione derivatives

Agreen regioselective synthesis of some new and known 9-aryl-5,9-dihydropyrimido[4,5-d][l,2,4]triazolo[1,5-a]pyrimidine-6,8（4H,7H）-diones has been described via the microwave-assisted one-pot reaction of 3-amino-1H-1,2,4-triazoles,aromatic aldehydes and barbituric acids under solvent- and catalyst-free conditions.This operationally simple procedure is less laborious and provides a better scope than previously reported procedures.

Determination of barbiturates in hair samples by using a validated UHPLC-HRMS method: application in investigation of drug-facilitated sexual assault

In recent years,benzodiazepines and benzodiazepine-like drugs are the most common substances associated with drug-facilitated sexual assaults(DFSA);however,barbiturates are also detected occasionally.Segmental hair analysis provides useful information on the historic pattern of drug use,enabling differentiation between single exposure in DFSA cases and chronic use.However,sensitive and specific methods for barbiturate analysis in hair samples are needed.Herein,we present an ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry(UHPLC-HRMS)method for qualitative and quantitative determination of seven barbiturates in hair samples.Firstly,a hair strand was decontaminated and then freeze-milled in liquid nitrogen.Next,50mg of powdered hair was extracted with methanol in an ultrasonic bath for 10 min in the presence of 10 ng phenobarbital-d5.The supernatant was dried under nitrogen gas,and the pellet was dissolved in 100 μL mobile phase.Afterwards,10 μL of the suspension was injected into the UHPLC-HRMS system.The present method involved two UHPLC conditions for determination of barbiturates(I)and identification of the structural isomers amobarbital and pentobarbital(II).This method showed satisfactory linearity in a range of 0.02–20.00 ng/mg for UHPLC conditions I and II,both with a high determination coefficient(0.9991–0.9999).The selectivity,intra-and interday precision,accuracy and matrix effect of the method were acceptable.Next,the validated method was applied to investigate an authentic DFSA case.Hair samples(black,approximate 25cm long)were collected 3 months after the assault,and the proximal segments(0–5 cm from the root;each segment was 1 cm long)were analysed.Amobarbital was detected at a concentration of<LOQ(limit of quantification)and 0.09 ng/mg in the second and third 1-cm hair segment but not in the other segments.Thus,our method was successful in determining barbiturate concentration in human hair after a single-dose exposure,showing its potential for application in the investigation of DFSA cases.

RETENTION PREDICTION OF CONJUGATED BILE ACIDS AND BARBITUR ATES BY USING INTER ACTION INDEX IN REVERSED PHASE LIQUID CHROMATOGRAPHY

Ⅰ. INTRODUCTION Recently, reversed phase liquid chromatography (RPLC) has become a very efficient standard technique for the modern analyses and is widely used for the analysis of many types of compounds. Retention prediction plays an important part in the thermodynamic studies in RPLC. Many attempts have been made to establish Kováts-like retention

Survival after pentobarbitone overdose confirmed through Prescription,Recreational and Illicit Substance Evaluation(PRISE)programme in Australia

Deaths caused by barbiturate overdoses have increased in the past decade,especially as a result of suicide attempts.Pentobarbitone is a central nervous system depressant used for sedation and euthanasia in veterinary medicine.However,pentobarbitone analysis is not commonly available in the hospital setting;hence,its occurrence in overdoses is under-reported.Herein we describe a patient who ingested pentobarbitone obtained from the Internet with the purpose of ending his life.He became comatose and required ventilation for 6 days.While critically ill,the drug and a barbiturate test kit were found in his room at his residence.Toxicological analysis of the patient’s blood determined the presence of pentobarbitone at levels of 91,56,and 19 mg/L at 11,59,and 107 h after ingestion,respectively.With supportive care,the patient made a full recovery.He stated that he believed the liquid was to be pentobarbitone,and that he had received advice on its use from an online forum that he had found on a dark web marketplace.In this report,we highlight the process by which we facilitated pentobarbitone analysis with a rapid turnaround time,which helped to inform clinical management and raise awareness among clinicians.The access was made through the Prescription,Recreational and Illicit Substance Evaluation(PRISE)programme,which is a collaborative network among the New South Wales(NSW)Ministry of Health,NSW Poisons Information Centre(PIC),and NSW Health Pathology Forensic&Analytical Science Service(FASS).

POLAROGRAPHIC ANALYSIS OF SODIUM 5-ALLYL-5- (I-METHYLBUTYL) BARBITURATE

The conventional polarographic analysis of the barbituric acid derivatives has been reviewed. With regard to the a.c. oscillopolarography, studies on Veronal and Luminal were reported in (3)Recently, Prokes et al. have made a semiquantitative determination of 5 species of barbiturates (in urine) in the phosphate base solution, and J. E. S. Han et al. have studied thiopental in 0.1 M borax and thus furnishes the possibility of the quantitative analysis of the barbituric acid derivatives. But so far no report in this respect has been seen. Seconal [sodium 5-allyl-5-(1-methylbutyl) barbiturate] is a