Mataichi Sagi

Studies on as-triazine derivatives. VIII: Synthesis of 5-substituted 1,2,4-triazines

Synthese de chloro-5 phenyl-3 R-6 triazines-1,2,4 (A) (R=methyl ou phenyl) par deshydroxylation/chloration de R-6 phenyl-3 2H-triazines-1,2,4ones-5; reactions des composes A avec des alcoolates, des amines, des composes a methylene actif et des cetones sur le substituant chloro-5

Studies of as-Triazine Derivatives. XV. Intramolecular Reverse-Election Demand Diels-Alder Reaction of 1,2,4-Triazine Derivatives

This type ring-transformation(intramolecular reverse electron-demand Diels-Alder reaction) was applicable to the corresponding 3,5-diphenyl-1,2,4-triazine-6-carboxylic acid esters. According to the similar manner, benzofuro[2,3-b]pyridines, benzofuro[2,3-c]pyridines, and benzofuro[2,3-d]pyridines were synthesized in satisfactory yields. The Diels-Alder reaction of 3-(2-phenylethynylphenoxy)-1,2,4-benzotriazine afforded 11-phenylbenzofuro[2,3-b]quinoline.

Studies on as-Triazine Derivatives XIII. A Facile Synthesis of Fusaric Acid from Thienyl-as-triazine Derivatives

Reverse electron-demand Diels-Alder reaction of ethyl 6-(2-thienyl)-1,2,4-triazine-3-carboxylate with norbornadiene in boiling p-xylene followed by the elimination of cyclopentadiene (retro Diels-Alder reaction) gave 5-(2-thienyl)pyridine-2-carboxylate. Desulfurization of the thienyl-pyridine with Raney nickel and subsequent saponification afforded fusaric acid (5-butylpyridine-2-carboxylic acid)

Studies of as-Triazine Derivatives. X. Addition Reaction of Phenylmagnesium Bromide with 1,2,4-Triazines

Obtention des derives phenyl-5 puis diphenyl-5,6 puis triaryl-3,5,6 (la derniere addition se faisant avec le bromure de p-methoxyphenylmagnesium)

as-トリアジン誘導体の研究(第19報)血小板凝集抑制活性を持つ2,3-ジアリールピラジン及び2,3-ジアリールピリジン誘導体の合成

4,5-Diphenyl-2-ethoxypyrimidine (1), 3,4-diphenyl-6-ethoxypyridazine (2) and 2,3-diphenyl-5-ethoxypyrazine (3) were evaluated for inhibitory activity towards arachidonic acid-induced aggregation of rabbit blood platelet in vitro. 2,3-Diphenyl-5-ethoxypyrazine (3) exhibited significant inhibitory activity. Thus, various 5-substituted 2,3-bis(4-methoxyphenyl)pyrazines were synthesized by the nucleophilic substitution reaction of 5-chloro-2,3-bis(4-methoxyphenyl)pyrazine (9). In a similar manner, substituted 2,3-bis(4-methoxyphenyl)pyridines were prepared from 2,3-bis(4-methoxyphenyl)-6-methylsulfonylpyridine (17), which was synthesized by the cycloaddition retro Diels-Alder reaction of 5,6-bis(4-methoxyphenyl)-3-methylsulfonyl-1,2,4-triazine (16) with norbornadiene. Among the compounds prepared, 6-isopropoxy-2,3-bis(4-methoxyphenyl)-pyrazine (10f) showed the most potent inhibitory activity, which was more than the activity of anitrazafen[5,6-bis(4-methoxyphenyl)-3-methyl-1,2,4-triazine.

Synthesis of 6-alkylamino-3-pyridazinecarboxylic acid derivatives from methyl 6-chloro-3-pyridazinecarboxylate

The synthesis of methyl 6-alkylamino-3-pyridazinecarboxylates (4a-c) was accomplished by the following reaction sequence. On treatment of methyl 6-chloro-3-pyridazinecarboxylate (1) with methanolic ammonia, 6-chloro-3-pyridazinecarboxamide (5) was precipitated almost quantitatively, which reacted with primary alkylamines to give the corresponding 6-alkylamino-3-pyridazinecarboxamide (6a-c). These products were smoothly converted into the methyl esters (4a-c) by treatment with methanol in the presence of boron trifluoride etherate. The reaction of 1 with butylamine in THF gave a complicated mixture in which N-butyl-6-chloro-3-pyridazinecarboxamide(2), N-butyl-6-butylamino-3-pyridazinecarboxamide(3), 4b, and 1 were involved

Studies on as-triazine derivatives. XVII, Chlorination of 5,6-dimethyl-3-phenyl-as-triazine

Homolytic chlorination of 5,6-dimethyl-as-triazine with Cl 2 gave 6-dichloromethyl-5-trichloromethyl-as-triazine (I) selectively. Structural determination of I by chemical method and synthesis of 5-amino-6-formyl-as-triazine derivatives are described.