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Ring transformation of 1,5‐benzoxazepines into spirobenzoxazoles. Synthesis of pyrazolo[1′,5′:3,4][1,2,4]triazino‐[5,6‐ b ][1,5]benzoxazepines and spiro[benzoxazole‐2′(3′ H ),4(1 H )‐pyrazolo[5,1‐ c ][1,2,4]triazines]
Author(s) -
Kurasawa Yoshihisa,
Okiyama Mari,
Kamigaki Yumiko,
Kanoh Megumi,
Takada Atsushi,
Okamoto Yoshihisa
Publication year - 1988
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570250442
Subject(s) - chemistry , benzoxazole , ring (chemistry) , hydrochloride , hydrochloric acid , medicinal chemistry , phenol , alkylation , acetic acid , iodide , stereochemistry , transformation (genetics) , methyl iodide , isopropyl , organic chemistry , catalysis , biochemistry , gene
The reactions of the 3‐substituted 4‐amino‐8‐ethoxycarbonyl[5,1‐ c ][1,2,4]triazines 1 and 2 with o ‐amino‐phenol hydrochloride gave the pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6‐ b ][1,5]benzoxazepines 5 and 8 . The alkylation of 5 with methyl iodide and isopropyl iodide afforded the 6‐alkoxylpyrazolo[1′,5′:3,4][1,2,4]triazino‐[5,6‐ b ][1,5]benzoxazepines 6a and 6b , respectively. Refluxing of 5, 6a, 6b and 8 in hydrochloric acid/acetic acid resulted in ring transformation to produce the spiro[benzoxazole‐2′(3′ H ),4(1 H )pyrazolo[5,1‐ c ][1,2,4]‐triazines] 7a, 7b and 9 . The screening data of the above compounds was described.