• Journal of the Korean Chemical Society
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• v.23 no.2
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• pp.94-98
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• 1979

From the catalytic reductions of the respective 2-amino-, and 2-nitro-3,4-dihydro-5,6-dimethoxy-1(2H)-naphthalenone, a major reduction product of 2-amino-5,6-dimethoxy-1,2,3,4-tetrahydro-naphthalene was obtained, along with a minute amount of rearranged product, 5,6-dimethoxy-1,2,3,4-tetrahydro-2(1H)-naphthalenone. The unusual formation of 5,6-dimethoxy-1,2,3,4-tetrahydro-2(1H)-naphthalenone was verified on the basis of ir, and nmr spectra, and elemental analysis. A plausible mechanism for the rearrangement is proposed.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.336-340
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• 1995

3',5'-Dimethoxy-4'-(2-vinyloxyethoxy)-4-nitrostilbene 2 and 3',5'-dimethoxy-4'-(2-vinyloxyethoxy)-2,4-dinitrostilbene 5 were prepared by the reactions of 2-iodoethyl vinyl ether with 3',5'-dimethoxy-4'-hydroxy-4-dinitrostilbene 1 and 3',5'-dimethoxy-4'-hydroxy-2,4-dinitrostilbene 4, respectively. Monomers 2 and 5 were polymerized with cationic initiators to obtain polymers with 3',5'-dimethoxy-4'-oxy-4-nitrostilbene and 3',5'-dimethoxy-4'-oxy-2,4-nitrostilbene, which are presumably effective chromophores for second-order nonlinear optical application in the side chain. The resulting polymers 3 and 6 were soluble in DMSO and DMF. The inherent viscosities of the polymers were in the range of 0.28-0.33 dL/g in DMSO. Polymers 3 and 6 showed a thermal stability up to 250 ℃ in TGA thermogram, and the Tg values obtained from DSC thermograms were in the range of 81-87°.

• Journal of The Korean Society of Clinical Toxicology
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• v.5 no.1
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• pp.8-14
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• 2007

Purpose: Organophosphorus insecticides tend to be regarded as a homogeneous single entity. We aimed to determine whether organophosphate poisoning differs by subgroups in clinical features and severity. Methods: We retrospectively reviewed medical records of all patients with acute organophophorus poisoning from January 1998 to December 2006. We investigated clinical features, Glasgow coma scale (GCS), laboratory findings, QTc intervals, management, and outcomes. Results: A total of 109 patients were included. The dimethoxy group experienced significantly longer times than the diethoxy group for ventilation duration (0.6 day vs. 0.2 day, p=0.006), ICU duration (2.0 day vs. 0.8 day, p=0.037), and total admission duration (2.8 day vs. 0.9 day, p=0.008), except in cases of dichlorvos poisoning. Also, the GCS of the dimethoxy group (except with dichlorvos) was significantly lower than for the diethoxy group (dimethoxy, $11.2{\pm}5.2$ vs. diethoxy, $13.8{\pm}2.4$, p= 0.021). QTc intervals for the dimethoxy group (except with dichlorvos) tended to be somewhat greater than for the diethoxy group (dimethoxy, $452.9{\pm}16.1\;msec$ vs. diethoxy, $429.6{\pm}40.9\;msec$). There were 65 patients with dichlorvos ingestion, and 2 of these patients (3%) died. Conclusion: When compared to the diethoxy group, the dimethoxy group of organophosphates (with the exception of dichlorvos) were associated with poorer prognostic value for indicators such as GCS, QTc interval, requirement for intubation, ICU duration, and total admission duration. Within the dimethoxy group, patients with dichlorvos poisoning had relatively better prognoses than for the other dimethoxy group organophosphates studied.

• Journal of the Korean Chemical Society
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• v.21 no.3
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• pp.187-192
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• 1977

An alternate synthesis of 2-amino-5,6-dimethoxy-1,2,3,4-tetrahydronaphthalene hydrochloride from 2-nitro-3,4-dihydro-5,6-dimethoxy-1(2H)-naphthalenone,was described and compared the overall yields and experimental procedures with the previous synthetic routes obtained from Neber rearrangement product, 2-amino-3,4-dihydro-5,6-dimethoxy-1(2H)-naphthalenone hydrochloride.

• YAKHAK HOEJI
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• v.47 no.1
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• pp.1-4
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• 2003

In order to search the new serotonin bioisoster, 2-(5,6-dimethoxy-l-indenyl)ethyl amine(1) was synthesized. 3,4-Dimethoxybenzaldehyde, as starting material, was condensed with malonic acid in the presence of pyridine and piperidine to form 3,4-dimethoxycinnamic acid(2). Compound 2 was performed catalytic hydrogenation with 10％ Pd-C to give propanoic acid derivative 3, which was cyclized by Friedel-Crafts acylation to afford 5,6-dimethoxyindan-l-one(4). Compound 4 was reduced with NaBH$_4$ in ethanol to obtain l-indanol 5, and it was dehydrated to give 5,6-dimethoxy-l-indene(6). This compound was lithiated with 2.5M n-butyllithium and reacted with 1,2-dibromoethane to give 2-(5,6-dimethoxy-l-indenyl)ethyl bromide(7), and which was treated with anhydrous ammonia to synthesize compound 1.

• Polymer(Korea)
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• v.26 no.6
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• pp.701-709
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• 2002

To synthesize a new positive photosensitive polyimide precursor, parts of carboxylic acid groups in poly (amic acid) were esterified with 4,5-dimethoxy-2-nitrobenzyl bromide in the presence of K$_2$CO$_3$/HMPA followed by the chemical imidization of residual carboxylic acid units. The chemical structure of resulting polymer was characterized by $^1$H-NMR, UV/vis and FT-IR spectroscopic methods, and its thermal properties were examined by DSC and TGA. Upon UV irradiation, 4,5-dimethoxy-2-nitrobenzyl moiety underwent the photodegradation. As a result, the polymer became soluble in alkaline developer due to the formation of carboxylic acid moiety, which was used to make a micron-sized positive pattern. Sensitivity curves were obtained from the gel fraction experiments with respect to the various 4,5-dimethoxy-2-nitrobenzyl ester contents. From those curves, the sensitivity was ranged iron 4000 to 6000 mJ/㎠, and the contrast was measured to be from 3.1 to 4.9.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2337-2340
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• 2010

A series of new 6-aryl-3-(3,4-dimethoxy-phenyl)-2-phenylsulfanyl-imidazo[2,1-b]-thiazole (5a-c) and 6-aryl-2-benzenesulfonyl-3-(3,4-dimethoxy-phenyl)imidazo[2,1-b]- thiazole (6a-c) have been prepared and characterized by analytical and spectral methods. The title compounds 5a-c and 6a-c were obtained by the reaction of 4-(3,4-dimethoxy-phenyl)-5-phenylsulfanyl-thiazol-2-ylamine (3) and 5-benzenesulfonyl-4-(3,4-dimethoxy -phenyl)thiazol-2-ylamine (4) with various phenacyl bromides in anhydrous ethanol. These newly synthesized compounds (5a-c and 6a-c) were screened for their anthelmintic and anti-inflammatory activities, where they have displayed better activities.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.66-72
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• 2004

In this study, the effects of oxygen component in fuel and exhaust gas recirculation(EGR) method on the exhaust emissions has been investigated for a D.I. diesel engine. It was tested to estimate change of exhaust emission characteristics for the commercial diesel fuel and oxygenate blended fuel which has five kinds of blending ratio. Dimethoxy methane(DMM) contains oxygen component 42.5% in itself, and it is a kind of effective oxygenated fuel for reduction of smoke emission. It was affirmed that smoke emission was decreased with increasing of DMM blending ratio. But, NOx emission was increased compared with commercial diesel fuel. It was needed a NOx reduction counterplan that EGR method was used as a countermeasure for NOx reduction. It was found that simultaneous reduction of smoke and NOx emission was achieved with DMM blended fuel and cooled EGR method(1015%).

• Toxicological Research
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• v.12 no.2
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• pp.289-293
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• 1996

Our previous studies demonstrated that quinone (menadione) is cytotoxic to rat platelets. In an attempt to assess the relative contributions of redox cycling and/or arylation in quinone-induced cytotoxicity, we have studied three quinones with different mechanisms: 2, 3-dimethoxy-1, 4-naphthoquinone (DMNQ; pure redox cycler), menadione (both redox cycler and arylator), and 1, 4-benzoquinone (pure arylator). The order of redox cycling capacity in platelet rich plasma (PRP) isolated from rats was menadione>DMNQ>1, 4-benzoquonone, which was consistent with the previous studies using isolated hepatocytes. 1, 4-Benzoquinone was more toxic to rat platelets than menadione, while DMNQ did not cause cell death at all. Lactate dehydrogenase inhibition studies revealed that 1, 4-benzoquinone inhibited significantly in a time-dependent manner, while menadione and DMNQ did not at all. These results suggested that arylation by quinone compounds might play a critical role in quinone-induced cytotoxicity in rat platelets.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.266-268
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• 1980