• Archives of Pharmacal Research
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• v.10 no.3
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• pp.173-178
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• 1987

Several new pyrazolo [1, 5-a]-S-triazine, pyrazolo [4, 5, -elpyrimidine, pyrazolo [1, 5-a] pyrimidine derivatives were synthesized via condensation of 3-antipyrinyl-5-amino-pyrazole (2) with $\beta$$-bifunctional reagents. The azo analogues of pyrazolo [1, 5-a] pyrimidines ; i. e. pyrazolo [5, 1, c]-as-triazine and pyrazolo[5, 1, -c]-as-benzotriazine were synthesized by coupling of diazotized 2-with agents containing active hydrogen.

• Archives of Pharmacal Research
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• v.13 no.4
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• pp.306-309
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• 1990

The synthesis of 5-hyterocyclimethyl-2'-deoxyuridines (4a-f) has been accomplished by displacement reaction of 5-(bromomethyl)-3', 5'-di-O-acetyl-2'-deoxyuridine with heterocyclic compounds, followed by removal of acetyl protecting group with methanolic ammonia. The compoudns synthesized were evaluated the inhibitory effects on L1210 cell probiferation and antiviral activities against Herpes simplex virus type 1 (HSV-1) None of the compounds exhibited sufficient biological activities.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.247-250
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• 2001

2, 3-Dicyanopyrazine derivatives have been synthesized by condensation of diaminomaleonitrile(DAMN) and a -diketone compounds. Diaminomaleohitrile (DAMN) is well known as a tetramer of hydrogen cyanide and a useful compound in the chemical industry not on]y as a starting material for synthesis of various heterocyclic compounds but also as an intermediate for synthesis of glycine, adenine, guanine et al. (omitted)

• YAKHAK HOEJI
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• v.13 no.4
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• pp.139-143
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• 1969

In order to diminish the side effects of nitrogen mustard on cancertherapy, alkyl and heterocyclic radicals were introduced to nitrogen mustard base. The prepared new nitrogen mustard derivtives are N-bis($\beta$-chloroethyl)-2-furamide, 5-nitro-N-bis($\beta$-chloroethyl)-2-furamide and N-bis($\beta$-chloroethyl) ortamide hydrochloride.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.29-31
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• 1993

Benzoin condensation reactions of furfurals and thiophenecarboxaldehydes in the presence of substituted benzyl and alkyl thiazolium salts were examined in order to improve the yield of the reaction and to examine the effect of the electronic nature of the catalysts. Thiophene derivatives gave thenils as the major products in low yields while furan derivatives gave only furoins in moderate to high yields.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.32-38
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• 1993

3-(3-Bromotetrahydrofuran-2-yl)-3-cephem 7 was obtained from 3-(2-hydroxyethyl)vinyl-3-cephem 6 by the cyclization reaction using N-bromosuccinimide. Compound 5 was prepared by Wittig reaction, namely a coupling of cephem-derived triphenylphosphonium salt 3 with aldehyde component 4 in the presence of base.

• Bulletin of the Korean Chemical Society
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• v.3 no.4
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• pp.149-152
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• 1982

A new convenient method for the reduction of carboxylic acids to the corresponding alcohols via acyloxyborohydrides was explored. Acyloxyborohydrides, prepared from the reaction of various carboxylic acids and sodium borohydride, underwent reduction to the corresponding alcohols readily by the addition of dimethyl sulfate or Lewis acids, such as boron trifluoride etherate and triphenyl borate, presumably through acyloxyboranes. By utilizing this procedure, aliphatic and aromatic acids are rapidly and quantitatively reduced to the corresponding alcohols in terahydrofuran either at room temperature (or at $65^{\circ}$). This procedure provides selective reduction of carboxylic acids in the presence of halogen, nitro, and heterocyclic rings such as furan and thiophene.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.182.1-182.1
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• 2003

Flavonoids with oxygen atoms are known to have potent biological effect.They have been studied long as major antioxidants which protect cell membranes. Recent medical surveys show that increased intake of selenium decreases the risk of breast, colon, lung and prostrate cancer by preventing free radical generation. The flavonoids, isoflavonoids, and coumarins which form the bulk of these compounds are very polar and have limited use as drugs which have to pass through BBB(Brain Blood Barrier)The non-polar property is increased by exchange oxygen to selenium as a part of heterocyclic compound. (omitted)

• Archives of Pharmacal Research
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• v.16 no.4
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• pp.318-321
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• 1993

Cyanoaccetic acid hydrazide reacted with some 2-pyrazolin-5-one, isoxazol-5-one and 2-thiazolin-4-one and their ylidene derivatives to yield several new annelated pyran heterocycles. Structures wre established on the basis of elementary analyses and spectral data studies in addition to synthesis via other routes.

• Analytical Science and Technology
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• v.6 no.3
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• pp.307-311
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• 1993

Ionophore, which contains 5-membered heterocyclic compound, was prepared. $Mg^{2+}$ was determined by salting-out technique using ionophore as a chelating reagent. After $Mg^{2+}$ was extracted into the acetonitrile layer as a Mg-$(Ionophore)_2$ complex from acetate buffered aqueous solution by salting-out extraction technique, absorbance of complex was recorded by atomic absorption spectrophotometry. Optimum pH was between 2.5 and 5.0 for extraction and 1:2([$Mg^{2+}$]/[ionophore]) complex were formed. The range of detection was 0.24ppm~2.4ppm and $Ca^{2+}$ and EDTA were interfered in the determination of $Mg^{2+}$.