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Studies on the reactivity of new types of tetracyclic‐1,5‐benzoxazepines: Part V
Author(s) -
Sekhar Batchu Chandra,
Ramana Devalla Venkata,
Ramadas Sukuru Raghu
Publication year - 2001
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.5570380211
Subject(s) - chemistry , lithium aluminium hydride , lithium (medication) , acetic anhydride , aluminum hydride , imine , acetic acid , hydrolysis , catalytic hydrogenation , medicinal chemistry , organic chemistry , hydride , catalysis , hydrogen , methoxide , endocrinology , medicine
The syntheses of tetracyclic 1,5‐benzoxazepines 3a‐e from heterocyclic (3‐chloroaldehydes 1a‐e and 2‐aminophenol are reported herein (Scheme I). Attempted lithium aluminium hydride (LiAlH 4 ) reduction of the imine double bond in 3a‐e failed to furnish the corresponding saturated compounds 5a‐e. Attempted catalytic hydrogenation of 3a‐e in the presence of acetic acid and acetic anhydride gave surprisingly only the acetoxy derivatives 6a‐e in high yields (Scheme II). Base catalysed hydrolysis of acetoxy derivatives 6a‐e furnished, as expected, the corresponding phenolic derivatives 7a‐e , in moderate yields. Attempted cyclofunctionalization of 3a‐e either with mercaptoacetic acid or its methyl ester to obtain the new penta‐cyclic heterocycles 4a‐e was, however, not successful.