• Journal of the Korean Chemical Society
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• v.16 no.3
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• pp.189-192
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• 1972

2, 6-Disubstituted-3-pyridazinones were synthesized from the reaction of trichloroethylideneacetophenone with substituted phenylhydrazines. Trichloroethylideneacetophenone 2, 4-dinitrophenylhydrazone was isolated from the reaction of trichloroethylideneacetophenone with 2, 4-dinitrophenylhydrazine and it gave 2-(2, 4-dinitrophenyl)-6-phenyl-3-pyridazinone through ring closure. This indicates that pyridazinones are produced through hydrazone formation and ring closure as suggested previously. The effect of substituents of phenylhydrazine on the reaction was also discussed.

• YAKHAK HOEJI
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• v.57 no.5
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• pp.316-322
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• 2013

The new pyridazinone analogs were synthesized for development of candidates to retain anticancer activity. Various 6-substituted pyridazin-3(2H)-ones were prepared from the pyridazinyl chloride 3a~d via endothermic nucleophilic substitution with hydroxide ion as nucleophile for 2~48 h. Pyridazinyl chloride 3a~d could be converted to hydroxypyridazines (or pyridazin-3(2H)ones) using 1~5 equivalents of water (or 1 equivalent of sodium hydroxide) at reflux in DMF. The tautomerism of lactim form to lactam form was also accomplished in pyridazine derivatives. Formation of pyridazinones 10 was undertaken with stirring using sodium hydroxide at reflux in DMF for 2 h. Synthetic compounds were identified using NMR spectrum.

• Journal of the Korean Chemical Society
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• v.16 no.4
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• pp.229-231
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• 1972

2, 6-Disubstituted-3-pyridazinones were synthesized from the reaction of trichloroethylideneacetone with substituted phenylhydrazines. From the reaction of trichloroethylideneacetone with ο-nitrophenylhydrazine, pyridazinone derivative was not obtained, but ${\gamma},{\gamma}$-dichloro-${\gamma}$-(o-nitrophenylhydrazino)-ethylideneacetone was obtained in 24% yield.

• Journal of the Korean Chemical Society
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• v.19 no.1
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• pp.38-42
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• 1975

Chloral-2-acetothienone was synthesized from the condensation of 2-acetothienone with chloral, and trichloroethylidene-2-acetothienone was obtained from the dehydration of chloral-2-acetothienone. From the reaction of trichloroethylidene-2-acetothienone with phenylhydrazine or substituted phenylhydrazines 2-aryl-6-(2-thienyl)-3(2H)-pyridazinones were obtained. 3-(2-Thienyl)-5-trichloromethyl-2-pyrazoline was synthesized from the reaction of trichloroethylidene-2-acetothienone with hydrazine hydrate.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.230-234
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• 2011

The present study describes the synthesis of 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone derivatives. The synthesis of the first target compound, 4,5-dihydro-6-(4-methoxy-3-methylphenyl)-3(2H)-pyridazinone (1), was achieved by Friedel-Crafts acylation of o-cresyl methyl ether with succinic anhydride and subsequent cyclization of the intermediary g-keto acid with hydrazine hydrate. Condensation of compound 1 with aromatic aldehydes in the presence of sodium ethoxide affords the corresponding 4-substituted benzyl pyridazinones (3a-d). The dihydropyridazinone 1 underwent dehydrogenation upon treatment with bromine/acetic acid mixture to give (4). Pyridazine (5) has been synthesized upon the reaction of pyridazinone (1) with 1,3-diphenyl-2-propen-1-one under the Michael addition reaction. N-dialkylaminomethyl derivatives 6a-b have been obtained from the reaction of pyridazinone 1 with formaldehyde and secondary amine, whereas reaction of 1 with formaldehyde gives N-hydroxymethyl derivative (7). This study also includes the synthesis of the 3-chloropyridazine derivative 8 in excellent yield by heating pyridazinone 3b in phosphorus oxychloride. The behaviour of the chloro derivative toward sodium azide, benzyl amine and anthranilic acid was also studied. The proposed structures of the products were confirmed by elemental analysis, spectral data and chemical evidence.

• Journal of the Korean Chemical Society
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• v.17 no.1
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• pp.25-30
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• 1973

2,6-Disubstituted-3-pyridazinones were synthesized by the reactions of $\gamma$,$\gamma$,$\gamma$-trichloroethylidene-m-nitroacetophenone with phenylhydrazine and substituted phenylhydrazines, and hydrazone was isolated as an intermediate from the reaction with 2, 4-dinitrophenylhydrazine. From the reaction with hydrazine hydrate 3-(m-nitrophenyl)-5-trichloromethyl-2-pyrazoline was obtained in good yield. The effect of substituents on phenyl group in the reaction of $\gamma$,$\gamma$,$\gamma$-trichloroethylidene-m-nitroacetophenone with substituted phenylhydrazines was also discussed.