Severe liver injury and clinical characteristics of occupational exposure to 2-amino-5-chloro-N,3-dimethylbenzamide: A case series

Background:The 2-amino-5-chloro-N,3-dimethylbenzamide is a key intermediate in the synthesis of pesticides and pharmaceuticals.However,no literature currently exists on 2-amino-5-chloro-N,3-dimethylbenzamide poisoning in humans.This study aimed to reveal the health hazard of this chemical for humans and summarize the clinical characteristics of patients with occupational 2-amino-5-chloro-N,3-dimethylbenzamide poisoning.Methods:This observational study included four patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning from June 2022 to July 2022.The entire course of the incidents was described in detail.Blood 2-amino-5-chloro-N,3-dimethylbenzamide concentrations were detected by a mass spectrometer.Hema-toxylin and eosin staining was performed to assess liver injury,and immunofluorescence was used to evaluate hepatic mitophagy.Results:The 2-amino-5-chloro-N,3-dimethylbenzamide powder(99%purity)entered the human body mainly via the skin and respiratory tract due to poor personal protective measures.The typical course of 2-amino-5-chloro-N,3-dimethylbenzamide poisoning was divided into latency,rash,fever,organic dam-age,and recovery phases in accordance with the clinical evolution.Rash and fever may be the important premonitory symptoms for further organ injuries.The chemical was detected in the blood of all patients and caused multiple organ injuries,predominantly liver injury,including kidney,myocardium,and micro-circulation.Three patients recovered smoothly after comprehensive treatments,including artificial liver therapy,continuous renal replacement therapy,glucocorticoids,and other symptomatic and supportive treatments.One patient survived by liver transplantation.The postoperative pathological findings of the removed liver showed acute liver failure,and immunofluorescence staining confirmed the abundance of mitophagy in residual hepatocytes.Conclusions:This study is the first to elaborate the clinical characteristics of patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning.The chemical enters the body through the respiratory tract and skin during industrial production.The 2-amino-5-chloro-N,3-dimethylbenzamide poisoning causes multiple-organ dysfunction with a predominance of liver injury.Liver transplantation may be an effective option for patients with severe liver failure.The mechanisms of liver injury induced by 2-amino-5-chloro-N,3-dimethylbenzamide might involve abnormal mitochondrial function and mitophagy.

Synthesis and antiangiogenic activities of 5-amino-1,3-dihydro-1,3-dioxo-2H-isoindole-2-propanoic acid derivatives

Based on the structure-activity relationships and antiangiogenic mechanism of RGD-containing peptides, a series of 5-amino- 1,3-dihydro-1,3-dioxo-2H-isoindole derivatives were synthesized. The structures were characterized by ^1H NMR, MS and elementary analysis. There ability to inhibit angiogenesis were evaluated by chick embryo chorioallantoic membrane assay at 10^-5 mol/L. Compounds 7a and 7b displayed obvious antiangiogenic activity.

Removal of 5-Amino-2-chlorotoluene-4-sulfonic and Chlorhydric Acids From Wastewater by Weakly Basic Resin: Equilibrium and Kinetics

Objective To study the adsorption of 5-Amino-2-chlorotoluene-4-sulfonic (CLT) and chlorhydric (HCl) acids from wastewater by weakly basic resin. Methods The kinetics and isotherm were studied. Thermodynamic parameters for the adsorption of acids were calculated and discussed. Results The adsorption of CLT and HCl acids followed Langmuir isotherm and the first-order kinetics model. Conclusion The adsorptive affinity of the two acids on D301R is in the order of CLT acid 〉 HCl acid. CLT and HCl acids can be separated.

Syntheses and Characterization of Two New Alkaline Earth Metal-organic Topological Frameworks with 3-Amino-1H-1,2,4-triazole-5-carboxylate

Two new alkaline earth metal coordination polymers constructed from the deriva-tive of 1,2,4-triazole are presented herein,namely,{[Sr（AmTAZAc）2（H2O）]}（1） and {[Ba（AmTAZAc）2（H2O）]}（2）（AmTAZAc = 3-amino-1H-1,2,4-triazole-5-carboxylate）,which have been synthesized by using the layering method and structurally characterized by elemental analysis,IR,and single-crystal X-ray diffraction.Complexes 1 and 2 are isostructural,and both crystallize in the orthorhombic system,space group Fdd2.X-ray structural analysis shows that 1 or 2 has an intriguing 3-D infinite network of（318.438.510） topology based on a 2-D sheet structure of（4,4） net.The result shows that noncovalent interactions play an important role in strengthening the whole structures of the compounds.

Theoretical Study on the Reaction Mechanism of 2-Methoxybenzaldehyde,4-Bromo-indanone,Malononitrile and Ammonium Acetate One-pot to Form 6-(2-Methoxyphenyl)-2-amino-6-bromo-5H-indeno[1,2-b]pyridine-3-carbonitrile

The reaction mechanism of 2-methoxybenzaldehyde, 4-bromo-indanone, malononitrile and ammonium acetate one-pot to form 6-（2-methoxyphenyl）-2-amino-6-bromo-5 Hindeno[1,2-b]pyridine-3-carbonitrile was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Reaction pathways were investigated in this study. The result indicates that the reaction Re→ TSB1→IMB1→ TSB2→ IMB2→TSB3→IMB3→TSB4→IMB4→TSB5→IMB5→TSB6→IMB6→TSB7→IMB7→ TSB8→IMB8→TSB9→IMB9→P2 is the main pathway, the activation energy of which is the lowest. The dominant product predicted theoretically is in agreement with the experiment results.

A Facile Synthesis of 2-Amino-5-Cyano-4, 6-Disubstitutedpyrimidines under MWI

Microwave Assisted Organic Synthesis (MAOS) is energy efficient and effective tool to speed up the synthesis for drug discovery process. In the present study we report a novel protocol for the rapid, high throughput synthesis of mononuclear 2-amino-5-cyano-4,6-disubstituted pyrimidines, adaptable to parallel synthesis for compound libraries. The overall reaction time in hrs has been reduced to 25 - 50 minutes with improved yields.

2-碘-3-溴-5-氯吡啶的合成

标题化合物是一个重要的药物中间体。以2-氨基-5-氯吡啶为起始原料,经溴代和重氮化反应得到目标化合物,总收率为66.31%,其结构经~1HNMR、^(13)CNMR和MS确定。该方法具有成本低廉、操作简单且收率较高等优点,符合工业化生产的要求。

2-氨基-5-氯吡啶水杨醛Schiff碱及其配合物的固相合成研究

以2-氨基-5-氯吡啶、水杨醛为原料在室温条件下进行研磨,合成了2-氨基-5-氯吡啶水杨醛Schiff碱(HL=C12H9ClON2),然后加入过渡金属盐氯化镍(氯化钴、醋酸铜)继续研磨制得2-氨基-5-氯吡啶水杨醛Schiff碱金属配合物,用元素分析、IR、UV、1HNMR、荧光光谱、电导率等手段对配合物的结构进行了表征,确定了配合物的组成分别为NiL2、CoL2、CuL2。

4-氨基-2-氯嘧啶-5-羧酸的合成研究

文章介绍了4-氨基-2-氯嘧啶-5-羧酸化合物的合成路线的改进。以乙氧基甲叉丙二酸二乙酯(EMME)和尿素为原料,经环合、取代、水解四步反应,合成了目标化合物,并经MS和1HNMR进行了结构表征。此合成路线反应条件温和、原料易得、操作简便、适合于工业化生产。反应总收率为34.3%。

Auxiliary Ligands Mediated One- and Two-dimensional Cd(Ⅱ) Coordination Polymers Incorporating Methyl-3- hydroxy-5-carboxy-2-Thiophenecarboxylate Ligand

Two N-donor ligands mediated Cd（Ⅱ） coordination polymers, namely,[Cd（L）（dmpz）2]n （1） and {[Cd（L）（atr）05（H20）]（H2O）}n （2） （H2L = methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate, dmpz = 3,5-dimethylpyrazole, and atr= 4-amino-l,2,4-triazole）, havebeen produced. Their structures were characterized by single-crystal X-ray diffraction analysis,elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional （1D） chainstructure and is finally extended into a three-dimensional （3D） supramolecular architecturethough hydrogen bonding interactions. Compound 2 features a two-dimensional （2D） networkwith 4-connected sql topology based on dinuclear Cd（Ⅱ） clusters as nodes, which is alsoassembled into a 3D supramolecular architecture through hydrogen bonding interactions.Furthermore, compounds 1 and 2 exhibit high thermal stabilities and intense fluorescent emissionin the solid, and can be explored as potential luminescent materials.

Synthesis, Crystal Structure, Antibacterial Activities and Theoretical Computation of 3-(2-Hydroxybenzly)-4-(4-isopropylbenzyl- ideneamino)-(1H)-1,2,4-triazole-5-thione

The title compound C18H18N4OS has been synthesized by the reaction of 3-（2-hydroxy- benzyl）-4-amino-（1H）-1,2,4-triazole-5-thione with 4-isopropylbenzaldehyde in ethanol and characterized by IR, ^1H NMR spectra and elemental analysis. Its structure was determined by X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 11.605（2）, b = 7.401（1）, c = 20.339（2） A, β= 103.05（2）°, V= 1701.8（4） A^3, Z = 4, Mr = 338.42,μ = 0.202 mm^-1, Dc = 1.321 g/cm^3 and F（000） = 712. The structure was solved by direct methods and refined to R = 0.0428 and wR = 0.1069. Due to the intramolecular O-H…N hydrogen bond and π-π stacking interactions between the benzene （C（1）～C（6）） and triazole rings, the two planes are essentially coplanar. Their biological activities have been measured, showing this type of compound has certain antibacterial activity for Staphylococous aureus and Bacillus subtilis. Based on the quantum chemistry calculation at the RHF/6-31G level, the frontier orbitals and electrostatic potential of the title compound were also discussed.

2-氨基-3-氟吡啶的合成研究

以2,3-二氟-5-氯吡啶为原料,通过氨基化、还原两步反应制备标题化合物。经正交试验优化,在反应温度为120℃、反应时间为24 h、投料比为1∶12的条件下,氨基化反应收率可达85.94%。该路线简单易操作、成本低廉,反应温和、后处理简单,适合工业化生产,路线总收率可达77.52%。

Synthesis and Crystal Structure of Dinuclear Copper(Ⅱ)Complex Cu_2(μ-PhCOO)_4(amet)_2·2CH_3COCH_3

Reaction of copper powder, dibenzoyl peroxide and 2-amino-4methyl-5-ethoxycarbonyl thiazole (amet) by refluxing in acetone yielded the dinuclearcopper(Ⅱ) complex Cu2 (μ-PhCOO)4 (amet)2- 2CH3COCH3. Crystal structure determination showed that each copper atom is coordinated by four bridged benzoxy and oneamet molecule with an M-M bond (Cu-Cu (A) = 2.6899 (7 ) ), therefore the coor-dination environment around the copper center is a distorted square pyramid with N(1)at the apical position. Blocks of Cu2 (μ-PhCOO)4 (amet)2·2CH3COCH3 crystallize inthe triclinic space group Ph, with Mr= 1100.14, a= 9. 631 (1), b=10. 446 (2), c=12. 758(2) ; a=91. 31 (1), β=95. 50(1),γ= 94. 87(1)°, V=1272. 4(3), Z=1, Dc= 1. 436 g/cm3, F(000) = 570, μ=0. 986 mm-1 and R=0.033, Rw=0.049.The IR spectra, which are of great interest since the molecule has ketone, ester andcarboxylate group simultaneously, are also discussed.

5-Amino-4-oxopentanoic acid photodynamic diagnosis guided microsurgery and photodynamic therapy on VX2 brain tumour implanted in a rabbit model

Background Complete tumour resection is important for improving the prognosis of brain tumour patients. However, extensive resection remains controversial because the tumour margin is difficult to be distinguished from surrounding brain tissue. It has been established that 5-amino-4-0xopentanoic acid （5-aminolevulinic acid, ALA） can be used as a photodynamic diagnostic marker and a photosensitizer for photodynamic therapy in surgical treatment of brain tumours. We investigated the efficacy of ALA photodynamically guided microsurgery and photodynamic therapy on VX2 brain tumour implanted in a rabbit model. Methods Eighty New Zealand rabbits implanted with VX2 brain tumours were randomly assigned to five groups： control, conventional white light microsurgery, a photodynamic therapy group, a photodynamically guided microsurgery group and a group in which guided microsurgery was followed by photodynamic therapy. The VX2 tumour was resected under a surgical microscope. The tumour resection was confirmed with histological analysis. All animals were examined with MRI for presence of any residual tumour tissue. The survival time of each rabbit was recorded. Results All treatment groups showed a significantly extended survival time compared with the control group. Photodynamically guided microsurgery combined with photodynamic therapy significantly prolonged survival time, compared with guided microsurgery alone. MRI and the autopsy results confirmed removal of most of the tumours. Conclusions Our results suggest that photodynamically guided surgery and photodynamic therapy significantly reduce or delay local recurrence, increase the effectiveness of radical resection and prolong the survival time of tumour bearing rabbits. Their combination has the potential to be used as a rapid and highly effective treatment of metastatic brain tumours.

Preparation of 2-amino-5,7-dimethoxy-4-aryl/alkyl-4H-chromene-3-carbonitriles using Na_2O-Al_2O_3-P_2O_5 glass–ceramic system

A highly efficient and environmentally benign protocol for the synthesis of 2-amino-5,7-dimethoxy-4- aryl/alkyl-4H-chromene-3-carbonitrile derivatives by one-pot three-component coupling reacting of aromatic aldehydes, malononitrile and 3,5-dimethoxy phenol under reflux condition has been developed in aqueous EtOH media using Na2O-Al2O3-P2O5 glass-ceramic system.

Structure identification of 4-amino-2-(arylamino)thiazole-5-carboxylic esters

In our previous work,we found a new method by chance for the synthesis of thiazole derivatives with diversified substitutes on 2-and 5-positions of the thiazole scaffold which was published in Chinese Chemical Letters[2014,Vol.25 p.411].The structures were identified by ~1H NMR,^（13）C NMR and HRMS as 2-alkoxy-4-amino-Narylthiazole-5-carboxamides.

Improvement in the synthesis of 2-(5-amino-1,2,4-thiadiazol-3- yl)-2-(Z)-methoxyiminoacetic acid 2-benzothiazolyl thioester

2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(Z)-meth-oxyiminoacetic acid 2-benzothiazolyl thioester(III),an important intermediate of the fourth generation cephalos-porins,was efficiently synthesized by reacting 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(Z)-methoxyiminoacetic acid(I)with 2,29-dibenzothiazole disulfide(II)in the presence of triphenylphosphine.Effects of reaction time,temperature,solvents,catalysts and feeding molar ratio on the yield and quality of products were investigated,and an im-proved procedure suitable for industrial production was established.Using 1,2-dichloroethane as solvent,triphe-nylphosphine as reducer,and triethylamine as catalyst,n(I):n(II):n(triphenylphosphine)51.0:1.0:1.0,the product was obtained at room temperature in 98.1%yield.The purity of the product without further purification is 98.7%determined by HPLC method.This procedure could be a suitable alternative to the traditional processes because of its easy handling,high yield and low cost.

佐匹克隆及其杂质对斑马鱼胚胎发育毒性的比较研究

目的对佐匹克隆及其主要杂质的斑马鱼胚胎发育毒性进行比较研究。方法以斑马鱼胚胎为实验对象,在体视光学显微镜下观察佐匹克隆及其主要杂质(杂质A、B、C和2-氨基-5-氯吡啶)在不同暴露浓度时对斑马鱼胚胎发育情况的影响,包括胚胎致畸、致死情况的检测与统计。结果佐匹克隆及其4个杂质对斑马鱼胚胎发育的毒性表型类似;毒性作用发生在胚胎器官的形成期;胚胎的畸形率和死亡率均呈一定的浓度依赖性升高;对胚胎发育的毒性由大到小的顺序为:杂质C、2-氨基-5-氯吡啶、杂质B、杂质A、佐匹克隆。结论结合佐匹克隆的杂质谱、佐匹克隆上市药品中杂质的检出情况以及佐匹克隆与其4个主要杂质对胚胎发育毒性的比较结果,建议重点关注佐匹克隆的主要降解杂质2-氨基-5-氯吡啶,并将其作为特定杂质,在原料与制剂现行标准中增加对该杂质的控制,以保证本品的安全性和质量可控性。

Estrogen affects neuropathic pain through upregulating N-methyl-D-aspartate acid receptor 1 expression in the dorsal root ganglion of rats

Estrogen affects the generation and transmission of neuropathic pain,but the specific regulatory mechanism is still unclear.Activation of the N-methyl-D-aspartate acid receptor 1（NMDAR1） plays an important role in the production and maintenance of hyperalgesia and allodynia.The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain.A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats.These rats were then subcutaneously injected with 17β-estradiol,the NMDAR1 antagonist D（-）-2-amino-5-phosphonopentanoic acid（AP-5）,or both once daily for 15 days.Compared with injured drug na？ve rats,rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency,indicating increased sensitivity to mechanical and thermal pain.Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity（as assessed by immunohistochemistry） and protein（as determined by western blot assay） in spinal dorsal root ganglia.This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5,whereas AP-5 alone did not affect NMDAR1 expression.These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve,and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.