Category: naphthyridine

Developmental phosphoproteomics identifies the kinase CK2 as a driver of hedgehog signaling and a therapeutic target in medulloblastoma was written by Purzner, Teresa;Purzner, James;Buckstaff, Taylor;Cozza, Giorgio;Gholamin, Sharareh;Rusert, Jessica M.;Hartl, Tom A.;Sanders, John;Conley, Nicholas;Ge, Xuecai;Langan, Marc;Ramaswamy, Vijay;Ellis, Lauren;Litzenburger, Ulrike;Bolin, Sara;Theruvath, Johanna;Nitta, Ryan;Qi, Lin;Li, Xiao-Nan;Li, Gordon;Taylor, Michael D.;Wechsler-Reya, Robert J.;Pinna, Lorenzo A.;Cho, Yoon-Jae;Fuller, Margaret T.;Elias, Joshua E.;Scott, Matthew P.. And the article was included in Science Signaling in 2018.Application In Synthesis of 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid This article mentions the following:

A major limitation of targeted cancer therapy is the rapid emergence of drug resistance, which often arises through mutations at or downstream of the drug target or through intrinsic resistance of subpopulations of tumor cells. To find new drug targets and therapeutics for MB that may be less susceptible to common resistance mechanisms, we used a developmental phosphoproteomics approach in murine granule neuron precursors (GNPs), the developmental cell of origin of MB. The protein kinase CK2 emerged as a driver of hundreds of phosphorylation events during the proliferative, MB-like stage of GNP growth, including the phosphorylation of three of the eight proteins commonly amplified in MB. CK2 was critical to the stabilization and activity of the transcription factor GLI2, a late downstream effector in SHH signaling. CK2 inhibitors decreased the viability of primary SHH-type MB patient cells in culture and blocked the growth of murine MB tumors that were resistant to currently available Hh inhibitors, thereby extending the survival of tumor-bearing mice. Because of structural interactions, one CK2 inhibitor (CX-4945) inhibited both wild-type and mutant CK2, indicating that this drug may avoid at least one common mode of acquired resistance. These findings suggest that CK2 inhibitors may be effective for treating patients with MB and show how phosphoproteomics may be used to gain insight into developmental biol. and pathol. In the experiment, the researchers used many compounds, for example, 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6Application In Synthesis of 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid).

5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6) belongs to naphthyridine derivatives. The naphthyridines have 10 delocalized π-electrons located in five molecular orbitals, each of which is distorted by the presence of the nitrogen atoms causing an electron drift in that direction. Transition metal complexes of 1,5-naphthyridine (1,5-napy) seems to form one-dimensional coordination polymers with the ligand acting as bidentate in a “stepped” bridging fashion.Application In Synthesis of 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

Design, Characterization, and Application of a pH-Triggered In Situ Gel for Ocular Delivery of Vinpocetine was written by Ma, Qun;Luo, Rui;Zhang, Huimin;Dai, Manman;Bai, Luyu;Fei, Qingsong;Lei, Fang;He, Ning. And the article was included in AAPS PharmSciTech in 2020.Quality Control of (41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate This article mentions the following:

Abstract: We developed a pH-triggered in situ gel (ISG) for ocular delivery of vinpocetine to achieve systemic absorption and a brain-targeting effect in rats. Carbopol acted as a gelling agent combined with hydroxypropyl methylcellulose (HPMC) as a viscosity-enhancing agent. The concentration of Carbopol (0.2%, w/v) and HPMC (1.5%, w/v) was optimized for the ISG system. The optimized formulation was evaluated for studies on release in vitro, rheol., differential scanning calorimetry, ocular irritation, residence time, and in vivo pharmacokinetics. The vinpocetine ISG stayed longer in rabbit eyes than vinpocetine ointment. In vivo pharmacokinetics showed that compared with vinpocetine ointment, vinpocetine ISG attained a peak plasma concentration and area under the curve that was 1-2 folds greater in rat plasma. The Drug Targeting Index (DTI) was 1.06 and 1.26 for vinpocetine ointment and vinpocetine ISG, resp., after ocular administration, showing that vinpocetine ISG had better distribution in rat brain. These results revealed that a pH-triggered ISG system via ocular administration could be an alternative approach compared with traditional ophthalmic formulations. In the experiment, the researchers used many compounds, for example, (41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate (cas: 42971-09-5Quality Control of (41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate).

(41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate (cas: 42971-09-5) belongs to naphthyridine derivatives. The naphthyridines have 10 delocalized π-electrons located in five molecular orbitals, each of which is distorted by the presence of the nitrogen atoms causing an electron drift in that direction. 1,6-Naphthyridine and some of its derivatives have been reported to have medicinal, electronic, and catalytic properties. But none of these investigations has yet resulted in any practical applications.Quality Control of (41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

Metabolite profiling of fruit and seed extracts of Garcinia xanthochymus using Rp-Hplc- Esi-Q-Tof-Ms and progenesis Qi was written by Sh, Nanjegowda;Mg, Papanna;Tr, Bharathi;Rr, Raghu Ram Achar;Hs, Prakash;Sn, Swamy;P, Mallu. And the article was included in Pharma Chemica in 2018.Recommanded Product: 42971-09-5 This article mentions the following:

Natural products research is the most enormous field of research in terms of the amount of data and importance of information. Natural products discovery and metabolomics deals with a crucial mode of representation of the profile of biol. active metabolites. In this regard, the profiling of the chem. makeup of complex natural plant extracts necessarily requires employing sophisticated and advanced anal. methods like RP-HPLC-ESI-Q-TOF-MS as well as data mining and processing methods. The genus Garcinia (Clusiaceae) contains phenolic, flavonoids, xanthones, triterpenes, and benzophenones which have been reported for their significant biol. properties. Due to its high content of secondary metabolites and its large domestic usage, we have developed a simple, rapid and precise method to characterize all the secondary metabolites using Reverse-Phase Ultra Performance Liquid Chromatog. coupled to Electrospray Ionization Quadruple Time-of-Flight Mass Spectrometry (RP-HPLC-ESI-Q- TOF-MS) for the hydro-methanolic extract A total of about 3443 secondary metabolites from the fruit and 3757 secondary metabolites from the seed were identified by the Progenesis-QI data anal. Among these a total of 74 compounds from fruits and 86 polar compounds from seeds were manually identified using the mass error limit of < ± 5 ppm including the score less than 40. The unexplored bioactives belonging to the class of glycosides, flavones, xanthones, organic acids and other phenolic derivatives Garcinia xanthochymus was found to contain significant number of diverse phytochem. components. These results indicate the profile of mols. present in G. xanthochymus and will be helpful for industries and researchers involved in isolation of their mols. of interest. In the experiment, the researchers used many compounds, for example, (41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate (cas: 42971-09-5Recommanded Product: 42971-09-5).

(41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate (cas: 42971-09-5) belongs to naphthyridine derivatives. Six naphthyridine isomers are white solids with a surprisingly wide span of melting points: 1,6-Naphthyridine’s is the lowest at <40 ºC; 2,6-naphthyridine’s is the highest at 114–115 ºC. Very few metal complexes of naphthyridines other than 1,8-naphthyridine have been described.Recommanded Product: 42971-09-5

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

Effects of vinpocetine combined with batroxobin on blood glucose, hearing, and serum levels of visfatin and ENA-78 in elderly patients with type 2 diabetes mellitus and deafness was written by Wang, Jing;Zhu, Lu-ming;Yang, Bing;Li, Li;Jiang, Li-li;Le, Ting;Tu, Xiao-hong. And the article was included in Shiyong Yaowu Yu Linchuang in 2021.Recommanded Product: 42971-09-5 This article mentions the following:

Objective To investigate the effects of vinpocetine combined with batroxobin on hearing, blood glucose, and serum levels of visfatin and ENA-78 in elderly patients with type 2 diabetes mellitus and deafness. Methods A total of 94 elderly patients with type 2 diabetes mellitus with deafness receiving treatment from July 2016 to July 2019 were randomly divided into observation group and control group by random number table method, 47 cases each. All patients received hypoglycemc treatment and the basic treatment of improved cochlear microcirculation and nerve nutritional. Both groups were treated with batroxobin injection by i.v. dripping 10 BU/time, once every 2 days, for 10 days. The observation group was addnl. treated with vinpocetine by i.v. infusion, 20 mg/time, once every 2 days, for 10 days. The total effective rate, fasting blood glucose and pure tone threshold at different time points before and after treatment, serum levels of visfatin and ENA-78 before and after treatment, high-cut viscosity of whole blood, low-cut viscosity of whole blood and plasma viscosity were compared. The correlation between pure tone threshold and serum levels of visfatin and ENA-78 was analyzed. Results The total effective rate of observation group was 89.36%, which was higher than 72.34% of the control group (P<0.05). The fasting blood glucose before treatment was comparable between the two groups (P>0.05). At different time points after treatment, the fasting blood glucose of the two groups was lower than that before treatment (P<0.05), but the difference between the two groups was not statistically significant (P>0.05), and no hypoglycemia events were observed during the treatment. At different time points after treatment, the pure tone hearing threshold of the two groups was lower than that before treatment (P<0.05). The pure tone thresholds of the observation group at 8 and 10 days after treatment were (52.60±3.11) dB, (48.42±2.02) dB, which were lower than those of the control group [(55.71±3.32) dB, (52.61±2.97) dB] with statistical significance (P<0.05). After 10 days of treatment, serum visfatin and ENA-78, whole blood high-cut viscosity, whole blood low-cut viscosity and plasma viscosity of the two groups were lower than those before treatment (P<0.05), and the decrease of the observation group was even larger (P< 0.05). There was a significant pos. correlation between pure tone threshold and serum visfatin (r=0.75, P<0.001), and a pos. correlation with serum ENA-78 (r=0.72, P<0.001). There was no significant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion Batroxobin combined with vinpocetine can play a synergistic role in the treatment of elderly type 2 diabetes with deafness, promoting the improvement of blood rheol. and down-regulating serum visfatin, ENA-78, which promotes the recovery of hearing. Its effect is better than single batroxobin, and has higher security. In the experiment, the researchers used many compounds, for example, (41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate (cas: 42971-09-5Recommanded Product: 42971-09-5).

(41S,13aS)-Ethyl 13a-ethyl-2,3,41,5,6,13a-hexahydro-1H-indolo[3,2,1-de]pyrido[3,2,1-ij][1,5]naphthyridine-12-carboxylate (cas: 42971-09-5) belongs to naphthyridine derivatives. Six naphthyridine isomers exist, based on the positions of the nitrogen atoms; they can be in the 1,5, 1,6, 1,7, 1,8, 2,6, or 2,7 positions. 1,6-Naphthyridine and some of its derivatives have been reported to have medicinal, electronic, and catalytic properties. But none of these investigations has yet resulted in any practical applications. Very few metal complexes of naphthyridines other than 1,8-naphthyridine have been described.Recommanded Product: 42971-09-5

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

Emerging JWA-targeted Pt(IV) prodrugs conjugated with CX-4945 to overcome chemo-immune-resistance was written by Chen, Feihong;Pei, Sinan;Wang, Xing;Zhu, Qian;Gou, Shaohua. And the article was included in Biochemical and Biophysical Research Communications in 2020.Application of 1009820-21-6 This article mentions the following:

Two Pt(IV) prodrugs, Cx-platin-Cl and Cx-DN604-Cl, derived from the conjugation of cisplatin or DN604 with a CK2 inhibitor CX-4945, were constructed to suppress DNA damage repair-related elements. During in vitro biol. studies, the Pt(IV) prodrugs had excellent cytotoxicity superior to cisplatin and DN604 to reverse drug resistance. Further mechanistic investigations revealed that the powerful anticancer activity of Cx-platin-Cl and Cx-DN604-Cl arisen from its suppression of JWA-XRCC1-mediated single-strand breaks repair. The emerging Pt(IV) prodrugs inhibited the growth of the xenografted tumors of C57BL6 and nude mice apart from JWA^-/- mice. Between them, Cx-platin-Cl augmented the infiltration and proliferation of T_eff cells, alleviated the recruitment of T_reg cells. The results provided compelling preclin. support that Cx-platin-Cl and Cx-DN604-Cl could reverse chemo-immune resistance via decaying JWA-XRCC1-mediated SSBR and immunosuppression, improving the development of emerging Pt(IV) candidate as a potential immunotherapeutic agent for cancer resistant prevention. In the experiment, the researchers used many compounds, for example, 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6Application of 1009820-21-6).

5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6) belongs to naphthyridine derivatives. Six naphthyridine isomers are white solids with a surprisingly wide span of melting points: 1,6-Naphthyridine’s is the lowest at <40 ºC; 2,6-naphthyridine’s is the highest at 114–115 ºC. Halogen atoms attached to the naphthyridine moiety can be easily replaced by other nucleophiles such as alkoxides and amines.Application of 1009820-21-6

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

Phosphorescence of aromatic molecules was written by Knuts, Soeren;Agren, Hans;Minaev, Boris F.. And the article was included in Journal of Molecular Structure: THEOCHEM in 1994.Application of 253-50-9 This article mentions the following:

Quadratic response theory for singlet and triplet operators (O. Vahtras et al., 1992) was recently applied to series of small mols. as well as to several aromatic compounds A comparative anal. of the results of such calculations on the phosphorescence effect in benzene, naphthalene and various azabenzenes and azanaphthalenes is presented. The information gained from such calculations concerns polarization directions, oscillator strengths, radiative lifetimes and excitation energies for the triplet states. These quantities either refer to values averaged over the triplet states or to the specific triplet state spin sublevels. The vibronically induced phosphorescence problem, with specific reference to benzene phosphorescence which is forbidden both by spin and orbital symmetry and only allowed through the coupling of nuclear and electronic motions is also discussed. Results are compared with vapor phase data concerning total radiative lifetimes, and with data from phosphorescence microwave double resonance measurements of matrix isolated samples concerning the spin sublevel rates. In the experiment, the researchers used many compounds, for example, 2,6-Naphthyridine (cas: 253-50-9Application of 253-50-9).

2,6-Naphthyridine (cas: 253-50-9) belongs to naphthyridine derivatives. Six naphthyridine isomers are white solids with a surprisingly wide span of melting points: 1,6-Naphthyridine’s is the lowest at <40 ºC; 2,6-naphthyridine’s is the highest at 114–115 ºC. Very few metal complexes of naphthyridines other than 1,8-naphthyridine have been described.Application of 253-50-9

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

An eco-sustainable green approach for the synthesis of 2,6-naphthyridines under microwave irradiation was written by Srivastava, K. P.;Singh, Indu;Kumari, Anupma. And the article was included in Pharma Chemica in 2014.Application In Synthesis of 2,6-Naphthyridine This article mentions the following:

A microwave-promoted new easy, efficient, clean and environmentally benign method for the synthesis of 2,6-naphthyridine and its derivatives from 4-cyano-3-pyridylacetonitrile has been developed. The desired products were isolated in excellent yields and high purity under eco-friendly conditions. In the experiment, the researchers used many compounds, for example, 2,6-Naphthyridine (cas: 253-50-9Application In Synthesis of 2,6-Naphthyridine).

2,6-Naphthyridine (cas: 253-50-9) belongs to naphthyridine derivatives. The naphthyridine ring system, being very π-deficient, is highly vulnerable towards nucleophilic attack, and consequently there has been extensive investigation of reactions involving nitrogen nucleophiles. Imidazonaphthyridines have been prepared through a ‘one-pot’ three-component ‘domino’ reaction between the keto-ester, acrolein, and ethylenediamine in presence of 4 Å molecular sieves.Application In Synthesis of 2,6-Naphthyridine

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

ROCK2-Specific Inhibitor KD025 Suppresses Adipocyte Differentiation by Inhibiting Casein Kinase 2 was written by Tran, Nhu Nguyen Quynh;Chun, Kwang-Hoon. And the article was included in Molecules in 2021.Application In Synthesis of 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid This article mentions the following:

KD025, a ROCK2 isoform-specific inhibitor, has an anti-adipogenic activity which is not mediated by ROCK2 inhibition. To identify the target, we searched binding targets of KD025 by using the KINOMEscanTM screening platform, and we identified casein kinase 2 (CK2) as a novel target. KD025 showed comparable binding affinity to CK2α (Kd = 128 nM). By contrast, CK2 inhibitor CX-4945 and ROCK inhibitor fasudil did not show such cross-reactivity. In addition, KD025 effectively inhibited CK2 at a nanomolar concentration (IC₅₀ = 50 nM). We examined if the inhibitory effect of KD025 on adipocyte differentiation is through the inhibition of CK2. Both CX-4945 and KD025 suppressed the generation of lipid droplets and the expression of proadipogenic genes Pparg and Cebpa in 3T3-L1 cells during adipocyte differentiation. Fasudil exerted no significant effect on the quantity of lipid droplets, but another ROCK inhibitor Y-27632 increased the expression of Pparg and Cebpa. Both CX-4945 and KD025 acted specifically in the middle stage (days 1-3) but were ineffective when treated at days 0-1 or the late stages, indicating that CX-4945 and KD025 may regulate the same target, CK2. The mRNA and protein levels of CK2α and CK2β generally decreased in 3T3-L1 cells at day 2 but recovered thereafter. Other well-known CK2 inhibitors DMAT and quinalizarin inhibited effectively the differentiation of 3T3-L1 cells. Taken together, the results of this study confirmed that KD025 inhibits ROCK2 and CK2, and that the inhibitory effect on adipocyte differentiation is through the inhibition of CK2. In the experiment, the researchers used many compounds, for example, 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6Application In Synthesis of 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid).

5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6) belongs to naphthyridine derivatives. The naphthyridines and their derivatives exhibit various types of biological activity, and the organic chemistry has been frequently reviewed. Imidazonaphthyridines have been prepared through a ‘one-pot’ three-component ‘domino’ reaction between the keto-ester, acrolein, and ethylenediamine in presence of 4 Å molecular sieves. The corresponding thiazolonaphthyridine is obtained from a similar reaction using 2-aminoethanethiol and Dowex basic anion-exchange resin.Application In Synthesis of 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

Casein Kinase II exacerbates rheumatoid arthritis via promoting Th1 and Th17 cell inflammatory responses was written by Ye, Hua;Fu, Dongdong;Fang, Xiangyu;Xie, Yang;Zheng, Xi;Fan, Wenqiang;Hu, Fanlei;Li, Zhanguo. And the article was included in Expert Opinion on Therapeutic Targets in 2021.SDS of cas: 1009820-21-6 This article mentions the following:

ObjectivesStudies have demonstrated that CK2 is engaged in CD4⁺ T cell proliferation and activation. We investigated the potential involvement of CK2 in the pathogenesis of rheumatoid arthritis (RA). Peripheral blood and synovial fluid mononuclear cells (PBMC and SFMC) of RA patients, as well as splenocytes of collagen-induced arthritis (CIA) mice were treated with different doses of CK2 inhibitor CX4945 in vitro. Then, the Th1, Th2, Th17, and Treg cell responses were analyzed. In addition, CIA mice were administrated with CX4945 via oral gavage. Accordingly, the arthritis scores, bone destruction, tissue damage, and the CD4⁺ T cell subsets were assessed. The expression of CK2 was upregulated in CD4⁺ T cells under RA circumstance. In vitro CX4945 treatment significantly inhibited the Th1 and Th17 cell responses, while promoted the Th2 cell responses in RA patient PBMC, SFMC and CIA mouse splenocytes, dampening IFN-γ and IL-17A production Moreover, administration of CX4945 ameliorated the severity of arthritis in CIA mice, along with decreased Th1 and Th17 cells. However, CX4945 seemed to have minimal effect on RA Treg cells. CK2 serves as an important regulator of the Th1 and Th17 cell axes in RA, thus contributing to the disease aggravation. In the experiment, the researchers used many compounds, for example, 5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6SDS of cas: 1009820-21-6).

5-((3-Chlorophenyl)amino)benzo[c][2,6]naphthyridine-8-carboxylic acid (cas: 1009820-21-6) belongs to naphthyridine derivatives. The naphthyridine ring system, being very π-deficient, is highly vulnerable towards nucleophilic attack, and consequently there has been extensive investigation of reactions involving nitrogen nucleophiles. Imidazonaphthyridines have been prepared through a ‘one-pot’ three-component ‘domino’ reaction between the keto-ester, acrolein, and ethylenediamine in presence of 4 Å molecular sieves. The corresponding thiazolonaphthyridine is obtained from a similar reaction using 2-aminoethanethiol and Dowex basic anion-exchange resin.SDS of cas: 1009820-21-6

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem

Syntheses and properties of 2,3-dibromo- and 2,3-dichloro-1,8-naphthyridines was written by Czuba, Wladyslaw;Wozniak, Marian. And the article was included in Roczniki Chemii in 1973.Safety of 2-Bromo-3-chloro-1,8-naphthyridine This article mentions the following:

Naphthyridinol I with KClO3 in concentrated HCl at 50° yielded 73% II, which heated at 125° with POBr3 gave 80% III. Similarly, II refluxed with POCl3 gave 98% IV. III and p-MeC6H4SO2-NHNH2 refluxed 24 hr in CHCl3 yielded 82% V.HBr; a similar reaction attempted with IV failed. V.HBr refluxed with aqueous Na2CO3 gave 28% VI. Analogs of II, IV, V, and VI with Br in place of Cl were prepared similarly. In the experiment, the researchers used many compounds, for example, 2-Bromo-3-chloro-1,8-naphthyridine (cas: 52626-32-1Safety of 2-Bromo-3-chloro-1,8-naphthyridine).

2-Bromo-3-chloro-1,8-naphthyridine (cas: 52626-32-1) belongs to naphthyridine derivatives. Six naphthyridine isomers are white solids with a surprisingly wide span of melting points: 1,6-Naphthyridine’s is the lowest at <40 ºC; 2,6-naphthyridine’s is the highest at 114–115 ºC. Halogen atoms attached to the naphthyridine moiety can be easily replaced by other nucleophiles such as alkoxides and amines.Safety of 2-Bromo-3-chloro-1,8-naphthyridine

Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem