Abstract:The polymerization of six spiro compounds such as
1-oxaspiro[2.5]octa-4,7-dien-6-one
(OSODO), spiro[anthrone-10,2‘-oxirane]
(SAO), and 5,7-dibromo-
(Br
2
-OSODO),
5,7-di-tert-butyl-
(tBu
2
-OSODO), 5,7-difluoro-
(F
2
-OSODO), and
4,5,7,8-tetrachloro-1-oxaspiro[2.5]octa-4,7-dien-6-ones
(Cl
4
-OSODO) were examined. Spiro compounds which carry substituents
at the 4 and 8 positions or bulky
substituents at the 5 and 7 positions such as SAO,
tBu
2
-OSODO, and
Cl
4
-OSODO were reluctant
to
undergo polyme… Show more
“…The quinones evaluated and used in the epoxidation reaction were extracted from the heartwood of Tabebuia spp. (Tecoma) and purified by recrystallization from ethanol as described in literature (Eistert et al 1962; Kubo et al 1998; Roush et al 1998), producing 14 compounds.…”
Section: Methodsmentioning
confidence: 99%
“…Eight naphthoxiranes were synthesized from the reaction of quinone in the presence of sodium hydride as the reducing agent in dimethyl sulphoxide (DMSO) (Sigma-Aldrich ® ) and further, trimethylsulphonium iodide was added under an inert atmosphere (Fig. 1) (Kubo et al 1998). Fig.…”
Human toxocarosis is a chronic tissue parasitosis most often caused by Toxocara canis. The seroprevalence can reach up to 50%, especially among children and adolescents. The anthelmintics used in the treatment have moderate efficacy. The aim of this study was to evaluate the in vitro and in vivo anthelmintic activity of quinones and their derivatives against T. canis larvae and the cytotoxicity of the larvicidal compounds. The compounds were evaluated at 1 mg mL(-1) concentration in microculture plates containing third stage larvae in an Roswell Park Memorial Institute (RPMI) 1640 environment, incubated at 37 °C in 5% CO2 tension for 48 h. Five naphthoxiranes were selected for the cytotoxicity analysis. The cell viability evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays using murine peritoneal macrophages isolated from C57BL/6 mice revealed that the naphthoxiranes (1 and 3) were less cytotoxic at a concentration of 0.05 mg mL(-1). The efficacy of naphthoxiranes (1 and 3) was examined in murine toxocarosis also. The anthelmintic activity was examined by evaluating the number of larvae in the brain, carcass, liver, lungs, heart, kidneys and eyes. Compound (3) demonstrated anthelmintic activity similar to that of albendazole by decreasing the number of larvae in the organs of mice and thus could form the basis of the development of a new anthelmintic drug.
“…The quinones evaluated and used in the epoxidation reaction were extracted from the heartwood of Tabebuia spp. (Tecoma) and purified by recrystallization from ethanol as described in literature (Eistert et al 1962; Kubo et al 1998; Roush et al 1998), producing 14 compounds.…”
Section: Methodsmentioning
confidence: 99%
“…Eight naphthoxiranes were synthesized from the reaction of quinone in the presence of sodium hydride as the reducing agent in dimethyl sulphoxide (DMSO) (Sigma-Aldrich ® ) and further, trimethylsulphonium iodide was added under an inert atmosphere (Fig. 1) (Kubo et al 1998). Fig.…”
Human toxocarosis is a chronic tissue parasitosis most often caused by Toxocara canis. The seroprevalence can reach up to 50%, especially among children and adolescents. The anthelmintics used in the treatment have moderate efficacy. The aim of this study was to evaluate the in vitro and in vivo anthelmintic activity of quinones and their derivatives against T. canis larvae and the cytotoxicity of the larvicidal compounds. The compounds were evaluated at 1 mg mL(-1) concentration in microculture plates containing third stage larvae in an Roswell Park Memorial Institute (RPMI) 1640 environment, incubated at 37 °C in 5% CO2 tension for 48 h. Five naphthoxiranes were selected for the cytotoxicity analysis. The cell viability evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays using murine peritoneal macrophages isolated from C57BL/6 mice revealed that the naphthoxiranes (1 and 3) were less cytotoxic at a concentration of 0.05 mg mL(-1). The efficacy of naphthoxiranes (1 and 3) was examined in murine toxocarosis also. The anthelmintic activity was examined by evaluating the number of larvae in the brain, carcass, liver, lungs, heart, kidneys and eyes. Compound (3) demonstrated anthelmintic activity similar to that of albendazole by decreasing the number of larvae in the organs of mice and thus could form the basis of the development of a new anthelmintic drug.
“…A fluorine-containing PPO derivative has much potential as new polymeric materials since it has excellent performances due to a PPO backbone bearing fluorine substituents. It was reported that poly(2,6-difluoro-1,4-phenylene oxide) ( 2 ) was synthesized by anionic polymerization of 5,7-difluoro-1-oxaspiro[2.5]octa-4,7-dien-6-one . This method, however, involves tedious multistep procedures including monomer synthesis and, hence, may not be suitable for preparative synthesis of 2 .…”
Section: Introductionmentioning
confidence: 99%
“…It was reported that poly(2,6-difluoro-1,4phenylene oxide) (2) was synthesized by anionic polymerization of 5,7-difluoro-1-oxaspiro[2.5]octa-4,7-dien-6one. 12 This method, however, involves tedious multistep procedures including monomer synthesis and, hence, may not be suitable for preparative synthesis of 2. Very recently, we have found that 2,6-difluorophenol (1) was polymerized by peroxidase catalyst.…”
Oxidative polymerization of 2,6-difluorophenol was performed using the Fe-salen complex and hydrogen peroxide as catalyst and oxidizing agent, respectively. The resulting polymer obtained at 60 °C in 1,4-dioxane was partly soluble in tetrahydrofuran and insoluble in chloroform, benzene, and hexafluorobenzene. The molecular weight of the THF-soluble part was in the range of several thousands. NMR and IR analysis showed the formation of poly(2,6-difluoro-1,4-phenylene oxide). In the DSC trace of second scan, the crystallization temperature and melting point were observed, indicating that the Fesalen complex enabled the synthesis of crystalline poly(phenylene oxide) from 2,6-difluorophenol for the first time.
“…In the previous papers, we reported a novel synthetic method for 2,6-disubstituted poly(1,4-phenylene oxide)s using oxaspiro compounds as starting materials (Scheme ). , Our proposed polymerization mechanism is shown in Scheme . The propagation reaction consists of two reaction steps.…”
The polymerization of 5,7-dichloro-1-oxaspiro[2.5]octa-4,7-dien-6-one (Cl2-OSODO) was
carried out in 2-methoxyethanol using potassium 4-methoxyphenoxide as an initiator. The molecular
weights of the polymers increased linearly with conversion. Monomer incremental addition and end-capping experiments exhibited the living characters of this polymerization. From kinetic studies of model
reactions, a combination of fast initiation and slow propagation rates in this polymerization system was
confirmed.
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