Tag: 200-300

Screening and Analysis of Multiclass Veterinary Drug Residues in Animal Source Foods using UPLC-Q-Exactive Orbitrap/MS was written by Zhao, Wentao;Jiang, Rui;Guo, Wenping;Guo, Chao;Li, Shilei;Wang, Juanqiang;Wang, Shouwei;Li, Yingying. And the article was included in Bulletin of Environmental Contamination and Toxicology in 2021.Synthetic Route of C11H12N4O3S This article mentions the following:

A rapid, simple, and sensitive method of detecting veterinary drug residues in animal food sources, including poultry and pork, was developed and validated. The method was optimized for over 155 veterinary drugs of 21 different classes. Sample pretreatment included a simple solid-liquid extraction step with 0.2% formic acid-acetonitrile-water and a purification step with a PRiME HLB (hydrophile-lipophile balance) solid-phase extraction cartridge. Data were collected using ultra-high-performance liquid chromatog. coupled to Quadrupole-Exactive Orbitrap mass spectrometry. The limits of detection of 155 veterinary drugs ranged from 0.1μg/kg to 10μg/kg. The recovery rates were between 79.2 and 118.5% in all matrixes studied, with relative standard deviation values less than 15% (n = 6). The evaluated method allows the reliable screening, quantification, and identification of 155 veterinary drug residues in animal source food and has been successfully applied in authentic samples. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3Synthetic Route of C11H12N4O3S).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. Pyrimidine is an aromatic heterocyclic organic compound similar to pyridine. For example, the neurotoxin tetrodotoxin is a pyrimidine derivative. It is found in a number of species including the Japanese puffer fish, the blue-ringed octopus, and the orange-bellied newt. Tetrodotoxin prevents the transmission of nerve signals and can result in paralysis and death.Synthetic Route of C11H12N4O3S

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Non-target, suspect and target screening of chemicals of emerging concern in landfill leachates and groundwater in Guangzhou, South China was written by Han, Yu;Hu, Li-Xin;Liu, Ting;Liu, Jing;Wang, Yu-Qing;Zhao, Jia-Hui;Liu, You-Sheng;Zhao, Jian-Liang;Ying, Guang-Guo. And the article was included in Science of the Total Environment in 2022.HPLC of Formula: 1220-83-3 This article mentions the following:

Landfill sites have been regarded as a significant source of chems. of emerging concern (CECs) in groundwater. However, our understanding about the compositions of CECs in landfill leachate and adjacent groundwater is still very limited. Here we investigated the CECs in landfill leachates and groundwater of Guangzhou in South China by target, suspect and non-target anal. using high-resolution mass spectrometry (HRMS). A variety of CECs (n = 242), including pharmaceuticals (n = 64), pharmaceutical intermediates (n = 18), personal care products (n = 9), food additives (n = 18), industrial chems. (n = 82, e.g., flame retardants, plasticizers, antioxidants and catalysts), pesticides (n = 26), transformation products (n = 8) and other organic compounds (n = 17) were (tentatively) identified by non-target and suspect screening. 142 CECs were quantitated with target anal., and among them 37, 24 and 27 CECs were detected resp. in the raw leachate (272-1780μg/L), treated leachate (0.25-0.81μg/L) and groundwater (0.10-53.7μg/L). The CECs in the raw leachates were efficiently removed with the removal efficiencies greater than 88.7%. Acesulfame, bisphenol F and ketoprofen were the most abundant compounds in both treated leachate and groundwater. The CECs in groundwater was found most likely to be originated from the landfill sites. Our results highlight the importance of non-target screening in identifying CECs, and reveal the contamination risk of groundwater by landfill leachate. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3HPLC of Formula: 1220-83-3).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. The pyrimidine nitrogenous bases are derived from the organic compound pyrimidine through the addition of various functional groups. Pyrimidine derivatives have been used in a wide variety of pharmaceuticals including general anesthetics, anti-epilepsy medication, anti-malaria medication, drugs for treating high blood pressure, and HIV medication.HPLC of Formula: 1220-83-3

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Development and evaluation of a semi-automatic single-step clean-up apparatus for rapid analysis of 18 antibiotics in fish samples was written by Mu, Shuhe;Teng, Tengwang;Zhou, Ruidong;Liu, Huan;Sun, Huiwu;Li, Jincheng. And the article was included in Journal of Food Composition and Analysis in 2022.Application In Synthesis of 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide This article mentions the following:

Here we report a novel semi-automatic pre-treatment apparatus to fulfill a single-step clean-up aim for rapid quantification of 18 antibiotics in fish samples. Trimethoprim and 17 sulfonamides were extracted from fish samples by acetonitrile solution based on ultrasonic-assisted extraction Cheap anal. filtration syringe (CAFS) clean-up column was used to fulfill single-step clean-up of the extract which was set on the developed semi-automatic clean-up apparatus This semi-automatic clean-up apparatus is quite convenient for single-step purification by precisely controlling the flow rate of the extracts, in which up to 10 samples can be purified in parallel at one time. The time needed to clean sample was only about 2 min per 10 samples. Type of compatible purification column ranged from 1 mL (inner diameter x length, 5.6 x 55 mm) to 12 mL (inner diameter x length, 15.6 x 83 mm). The apparatus also did not need addnl. gas source such as nitrogen or air. After purification, the analytes were simultaneously separated and quantified by high-performance liquid chromatog./quadrupole-linear ion trap tandem mass spectrometry (HPLC-QTRAP-MS/MS). The limits of detections ranged from 0.5 to 1.0μg kg-1, and the limits of quantifications ranged from 1.0 to 5.0μg kg-1. All the recoveries ranged from 81.39% to 116.01%. Intra-day and inter-day relative standard deviations (RSDs) were lower than 14% for all analytes. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3Application In Synthesis of 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. The aromatic compound pyrimidine, and its derivatives, are ubiquitous in nature. They are found in nucleic acids, vitamins, amino acids, antibiotics, alkaloids, and a variety of toxins. For example, the neurotoxin tetrodotoxin is a pyrimidine derivative. It is found in a number of species including the Japanese puffer fish, the blue-ringed octopus, and the orange-bellied newt. Tetrodotoxin prevents the transmission of nerve signals and can result in paralysis and death.Application In Synthesis of 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Design and synthesis of quinoline-pyrimidine inspired hybrids as potential plasmodial inhibitors was written by Kayamba, Francis;Malimabe, Teboho;Ademola, Idowu Kehinde;Pooe, Ofentse Jacob;Kushwaha, Narva Deshwar;Mahlalela, Mavela;van Zyl, Robyn L.;Gordon, Michelle;Mudau, Pertunia T.;Zininga, Tawanda;Shonhai, Addmore;Nyamori, Vincent O.;Karpoormath, Rajshekhar. And the article was included in European Journal of Medicinal Chemistry in 2021.Reference of 40230-24-8 This article mentions the following:

A series of novel N-(7-chloroquinolin-4-yl)-N’-(4,6-diphenylpyrimidin-2-yl)alkanediamine hybrids I (R = Me, MeO, OH; R¹ = 4-Cl, 4-MeO, 4-OH, 3,4-(MeO)₂; 3,4-OH₂; n = 2, 3, 4) and II (R² = H, 4-Me, 4-MeO, 3,4-(MeO)₂, 4-OH; R³ = H, 4-Cl, 4-MeO, 4-OH, 3,4-(MeO)₂; 3,4-OH₂) was designed, synthesized, and evaluated for their inhibitory activity against the NF54 chloroquine-susceptible strain as a promising class of antimalarial compounds The antiplasmodial screening revealed that seven analogs showed promising to good activity with half-maximal inhibitory concentration (IC₅₀) = 0.32μM-4.30μM. Compound I (R = OH; R¹ = 4-OH; n = 4) (III) with 1,4-diamine Bu linker and 4-hydroxyl Ph on fourth and sixth position of pyrimidine core showed the most prominent activity with an IC₅₀ value of 0.32 ± 0.06μM, with a favorable safety profile of 9.79 to human kidney epithelial (HEK293) cells. The remaining six analogs showed moderate activity with IC₅₀ values ranging from 7.50μM to 83.01μM. Further, the binding affinities of the mols. to two essential cytosolic P. falciparum heat shock protein 70 homologues; PfHsp70-1 and PfHsp70-z were investigated. Compound (III) exhibited the highest binding affinity for both PfHsp70s with KD in a lower nanomolar range (4.4-11.4 nM). Furthermore, mol. docking revealed that compounds I (R = OH; R¹ = 3,4-OH₂; n = 4), II (R² = R³ = 4-MeO, 3,4-(MeO)₂) and (III) exhibited better fitness in PfHsp70-1 with compound (III) showing the highest and lowest binding scores of -9.8 kcal/mol. Therefore, it is speculated that PfHsp70-1 is one of the targets of these inhibitors. The bioisoteric replacement of the groups at Ph ring at the fourth and sixth position of the pyrimidine core had a constructive association with antiplasmodial activity. The promising antiplasmodial activity of the synthesized analogs illustrates how crucial mol. hybridization is as a strategy in the development of quinoline-pyrimidine hybrids as prospective antiprotozoal agents. In the experiment, the researchers used many compounds, for example, 4,6-Diphenylpyrimidin-2-amine (cas: 40230-24-8Reference of 40230-24-8).

4,6-Diphenylpyrimidin-2-amine (cas: 40230-24-8) belongs to pyrimidine derivatives. Pyrimidine is an aromatic heterocyclic organic compound similar to pyridine. We all know its importance to life – pyrimidine and purine bases are included in the structure of DNA and RNA.Reference of 40230-24-8

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Microbiological inhibition-based method for screening and identifying of antibiotic residues in milk, chicken egg and honey was written by Wu, Qin;Shabbir, Muhammad Abu Bakr;Peng, Dapeng;Yuan, Zonghui;Wang, Yulian. And the article was included in Food Chemistry in 2021.Electric Literature of C11H12N4O3S This article mentions the following:

This present study was designed to develop a novel microbiol. inhibition-based method for the rapid screening and identification of antibiotic residues in milk, chicken egg and honey. Geobacillus stearothermophilus C953 was used as test bacterium in the detection system of this study. The optimization of nutrients and other supplements were performed to promote the growth of test bacterium and thus shorten the detection time. Furthermore, the synergetic agents were added to improve the sensitivity of test bacterium to more antibiotics. Addnl., confirmatory solutions such as β-lactamase, p-aminobenzoic acid, MgSO4 and cysteine were added to classify and identify different kinds of antibiotics. We observed that the LOD of this detection system was at or close to maximum residue limits established by EU for β-lactams, aminoglycosides, tetracyclines, sulfonamides, macrolides and quinolones in milk. The LOD of different kinds of antibiotics in chicken egg was less than or similar to the MRL and the LOD of Premitest (except sulfonamides). For honey, there are no MRL, the LOD was less than or similar to the recommended concentration and the LOD of Premitest. Noteworthy, the detection system also can identify these six kinds of antibiotics in milk, chicken egg and honey, and there were satisfactory results of specificity experiments and confirmation experiments by LC-MS/MS. Accordingly, the present study provides a reliable preliminary characterization of antibiotic residues in animal foods and improves the detection efficiency for the following chem. confirmation experiments by HPLC, LC-MS/MS, immunol. and receptor-based tests. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3Electric Literature of C11H12N4O3S).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. The pyrimidine nitrogenous bases are derived from the organic compound pyrimidine through the addition of various functional groups. A Cu-catalyzed and 4-HO-TEMPO-mediated [3 + 3] annulation of commercially available amidines with saturated ketones enables an efficient and facile synthesis of structurally important pyrimidines via a cascade reaction of oxidative dehydrogenation/annulation/oxidative aromatization.Electric Literature of C11H12N4O3S

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Antibiotics in the surface water of Shanghai, China: screening, distribution, and indicator selecting was written by Zhu, Feng;Wang, Siqi;Liu, Yujie;Wu, Minghong;Wang, Hongyong;Xu, Gang. And the article was included in Environmental Science and Pollution Research in 2021.Related Products of 1220-83-3 This article mentions the following:

The widespread existence of antibiotics has caused inevitable influence on ecol. and humans. In this study, we screened the most commonly used antibiotics, and 64 antibiotics were detected in Shanghai, an international metropolis. Most of the target substances were detected in all 46 water samples including main rivers and districts in Shanghai, with concentrations ranging from 0.02 to 502.43 ng L^-1. In particular, sulfadiazine (502.43 ng L^-1) had the highest maximum concentration Besides, risk quotients based on fish suggested that sulfonamides had a medium risk (0.12) in Shanghai. Correlation studies had shown that most compounds with frequencies exceeding 60% were significantly pos. correlated with the total concentration Based on further anal., sulfadiazine, sulfamerazine, and sulfapyridine were screened as indicators to reflect the pollution status of antibiotics in Shanghai for a long time. The screening conditions for these indicators include detection rate (> 60%), maximum concentration (> 100 ng L^-1), RQ (> 0.01), and correlation (> 0). In addition, population d. may be the main factor for antibiotic pollution through regional comparison. In a word, this work can systematically reflect the overall situation of Shanghai antibiotics and provide support for global data comparison in the future. Meanwhile, we provided the potential indicators that can be applied in the long term and economical monitoring of antibiotics. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3Related Products of 1220-83-3).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. The pyrimidine derivatives can easily interact with enzymes, genetic materials, and bio components within the cell. Therapy for fungal infections is based mainly on four classes of antifungals: azoles, echinocandins, polyenes, and pyrimidine analogs.Related Products of 1220-83-3

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Determining a wide range of antibiotics and pesticides in poultry feathers using selective accelerated solvent extraction-liquid chromatography-mass spectrometry was written by Wu, Huizhen;Zhou, Min;Xu, Jie;Wang, Jianmei;Tong, Jianying;Sun, Nabo;Qian, Mingrong. And the article was included in Analytical Methods in 2022.Product Details of 1220-83-3 This article mentions the following:

This study established a detection method based on accelerated solvent extraction-liquid chromatog.-mass spectrometry for determining residues of 3 chloramphenicols, 8 macrolides, 18 sulfonamides, 4 nitroimidazoles, 15 insecticides, and 22 fungicides in poultry feathers. The extraction solvent, methanol, was used for a static extraction time of 5 min, and repeated three times. Fifty milligrams of adsorbents C18/PSA (1 : 1, W/W) were added to the extraction cell to achieve simultaneous extraction and purification The extraction efficiency of three solvents, methanol, acetonitrile and Et acetate, was investigated. An orthogonal exptl. design was used to explore the optimal combination of extraction temperature, static extraction time, number of extraction cycles, and adsorbent ratio for accelerated solvent extraction After the optimal ratio was determined, the dosage of adsorbents was optimized. The extracted sample solution was concentrated by blowing nitrogen, redissolved, passed through a 0.22 μm PTFE membrane filter, then injected for instrumental anal. The validation results showed that the recovery of the proposed method was 60.4-107.6%, the limit of detection 0.2-3.0 μg kg^-1, and the limit of quantification 0.5-8.3 μg kg^-1. This quant. multi-residue detection method was able to determine the residues of 70 target compounds in poultry feathers. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3Product Details of 1220-83-3).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. The aromatic compound pyrimidine, and its derivatives, are ubiquitous in nature. They are found in nucleic acids, vitamins, amino acids, antibiotics, alkaloids, and a variety of toxins. We all know its importance to life – pyrimidine and purine bases are included in the structure of DNA and RNA.Product Details of 1220-83-3

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Elevated levels of antibiotic resistance in groundwater during treated wastewater irrigation associated with infiltration and accumulation of antibiotic residues was written by Kampouris, Ioannis D.;Alygizakis, Nikiforos;Kluemper, Uli;Agrawal, Shelesh;Lackner, Susanne;Cacace, Damiano;Kunze, Steffen;Thomaidis, Nikolaos S.;Slobdonik, Jaroslav;Berendonk, Thomas U.. And the article was included in Journal of Hazardous Materials in 2022.Application of 1220-83-3 This article mentions the following:

Treated wastewater irrigation (TWW) releases antibiotics and antibiotic resistance genes (ARGs) into the environment and might thus promote the dissemination of antibiotic resistance in groundwater (GW). We hypothesized that TWW irrigation increases ARG abundance in GW through two potential mechanisms: the contamination of GW with resistant bacteria and the accumulation of antibiotics in GW. To test this, the GW below a real-scale TWW-irrigated field was sampled for six months. Sampling took place before, during and after high-intensity TWW irrigation. Samples were analyzed with 16S rRNA amplicon sequencing, qPCR of six ARGs and the class 1 integron-integrase gene intI1, while liquid chromatog. tandem mass spectrometry was performed to detect antibiotic and pharmaceutical residues. Absolute abundance of 16S rRNA in GW decreased rather than increased during long-term irrigation. Also, the relative abundance of TWW-related bacteria did not increase in GW during long-term irrigation. In contrast, long-term TWW irrigation increased the relative abundance of sul1 and intI1 in the GW microbiome. Furthermore, GW contained elevated concentrations of sulfonamide antibiotics, especially sulfamethoxazole, to which sul1 confers resistance. Total sulfonamide concentrations in GW correlated with sul1 relative abundance. Consequently, TWW irrigation promoted sul1 and intI1 dissemination in the GW microbiome, most likely due to the accumulation of drug residues. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3Application of 1220-83-3).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. The pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives. Pyrimidine derivatives have been used in a wide variety of pharmaceuticals including general anesthetics, anti-epilepsy medication, anti-malaria medication, drugs for treating high blood pressure, and HIV medication.Application of 1220-83-3

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Continuous antibiotic attenuation in algal membrane photobioreactor: Performance and kinetics was written by Kiki, Claude;Ye, Xin;Li, Xi;Adyari, Bob;Hu, Anyi;Qin, Dan;Yu, Chang-Ping;Sun, Qian. And the article was included in Journal of Hazardous Materials in 2022.Reference of 1220-83-3 This article mentions the following:

The attenuation of 10 mixed antibiotics along with nutrients in a continuous flow mode by four freshwater microalgae (Haematococcus pluvialis, Selenastrum capricornutum, Scenedesmus quadricauda, and Chlorella vulgaris) was examined in membrane photobioreactors (MPBRs). At lab-scale, consistent removal of both antibiotic and nutrient was shown by H. pluvialis and S. quadricauda, resp. The system exhibited better performance with enhanced removal at HRT 24 h compared to 12 h and 48 h. The highest removal efficiency of antibiotics was observed in H. pluvialis MPBR, with the mean antibiotic removal values of 53.57%- 96.33%. Biodegradation was the major removal pathway of the antibiotics in the algal-MPBR (AMPBR), while removal by bioadsorption, bioaccumulation, membrane rejection, and abiotic was minor. Then, the bacterial feature was studied and showed significant influence from system hydrodynamics. The kinetics of continuous flow antibiotic removal followed Stover-Kincannon and Grau second-order models, which revealed great potential of AMPBR to withstand antibiotic load. The latter coupled with the computational fluid dynamic simulation was successfully applied for the residual antibiotic prediction and potential system optimization. Overall, these results provide an important reference for continuous flow antibiotic removal using AMPBR. In the experiment, the researchers used many compounds, for example, 4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3Reference of 1220-83-3).

4-Amino-N-(6-methoxypyrimidin-4-yl)benzenesulfonamide (cas: 1220-83-3) belongs to pyrimidine derivatives. The pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives. We all know its importance to life – pyrimidine and purine bases are included in the structure of DNA and RNA.Reference of 1220-83-3

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia

Discovery of 1-Methyl-1H-imidazole Derivatives as Potent Jak2 Inhibitors was written by Su, Qibin;Ioannidis, Stephanos;Chuaqui, Claudio;Almeida, Lynsie;Alimzhanov, Marat;Bebernitz, Geraldine;Bell, Kirsten;Block, Michael;Howard, Tina;Huang, Shan;Huszar, Dennis;Read, Jon A.;Rivard Costa, Caroline;Shi, Jie;Su, Mei;Ye, Minwei;Zinda, Michael. And the article was included in Journal of Medicinal Chemistry in 2014.Related Products of 938443-20-0 This article mentions the following:

Structure based design, synthesis, and biol. evaluation of a novel series of 1-methyl-1H-imidazole, as potent Jak2 inhibitors to modulate the Jak/STAT pathway, are described. Using the C-ring fragment from our first clin. candidate AZD1480 (I), optimization of the series led to the discovery of compound II, a potent, orally bioavailable Jak2 inhibitor. Compound II displayed a high level of cellular activity in hematopoietic cell lines harboring the V617F mutation and in murine BaF3 TEL-Jak2 cells. Compound II demonstrated significant tumor growth inhibition in a UKE-1 xenograft model within a well-tolerated dose range. In the experiment, the researchers used many compounds, for example, 2,4,7-Trichloropyrido[2,3-d]pyrimidine (cas: 938443-20-0Related Products of 938443-20-0).

2,4,7-Trichloropyrido[2,3-d]pyrimidine (cas: 938443-20-0) belongs to pyrimidine derivatives. Heterocyclic compounds bearing the pyrimidine core are of tremendous interest as they constitute an important class of natural and synthetic compounds exhibiting diverse useful biological activities that hold attractive potential for clinical translation as therapeutic agents in alleviation of a myriad of diseases. Drugs having the pyrimidine motif have manifested to exhibit gratifying biological activity like anticancer, antiviral, anti-inflammatory, antibacterial, and antihypertensive activities.Related Products of 938443-20-0

Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia