Abstract |
3-Methoxycarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline (11)과 p-fluorobenzenediazonium chloride를 반응시켜 3-[a-(p-fluorophenylhydrazono)methoxycarbonylmethyl]-1,2-dihydro-2-oxoquinoxaline (12)을 합성하였고, 이것을 phosphoryl chloride와 반응시켜 2-chloro-3-[a-(p-fluorophenylhydrazono)methoxycarbonylmethyl]quinoxaline (13)을 합성하였다. 화합물 13을 hydrazine hydrate와 반응시켜 분자내 고리화 반응으로 1-(p-fluorophenyl)-3-hydrazinocarbonyl-1H-pyrazolo[3,4-b]quinoxaline (14)을 합성하였고, 이것을 alkanoyl chloride류, benzoyl chloride류, 벤즈알데히드류 또는 isothiocyanate류와 반응시켜 1H-pyrazolo[3,4-b]quinoxaline류 15-18을 각각 합성하였다. 그리고 화합물 18을 2N NaOH 용액에서 환류시켜 1,2,4-triazolyl-1H-pyrazolo[3,4-b]quinoxaline류 (19)를 합성하였고, 화합물 17을 아세트산 무수물과 반응시켰더니 1,3,4-oxadiazolyl-1H-pyrazolo[3,4-b]quinoxaline류 (20)로 고리화반응이 일어났다.
The reaction of 3-methoxycarbonylmethylene-2-oxo-1,2,3,4-tetrahydroquinoxaline (11) with p-fluorobenzenediazonium chloride gave 3-[a-(p-fluorophenylhydrazono)methoxycarbonylmethyl]-1,2-dihydro-2-oxoquinoxaline (12), whose reaction with phosphoryl chloride provided 2-chloro-3-[a-(p-fluorophenylhydrazono)- methoxycarbonylmethyl] quinoxaline (13). The reaction of compound 13 with hydrazine hydrate resulted in the intramolecular cyclization to give 1-(p-fluorophenyl)-3-hydrazinocarbonyl-1H-pyrazolo[3,4-b]quinoxaline (14). The reaction of compound 14 with alkanoyl chlorides, benzoyl chlorides, benzaldehydes or isothiocyanates afforded 1H-pyrazolo[3,4-b]quinoxalines 15-18, respectively. Refluxing of compound 18 in 2N NaOH solution gave the 1,2,4-triazolyl-1H-pyrazolo[3,4-b]quinoxaline (19). The reaction of compounds 17 and acetic anhydride gave the cyclized compounds, 1,3,4- oxadiazolyl-1H-pyrazolo[3,4-b]quinoxalines (20).
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