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Synthesis of some pyrazolo[1,5‐ c ][1,3]benzoxazines and a new 5 H ‐pyrazolo[1,5‐c][1,3,2]benzoxazaphosphorine ring system
Author(s) -
Svetlik Jan,
Pronayova Nada,
Kubista Jiri
Publication year - 2005
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.5570420616
Subject(s) - chemistry , reagent , glyoxylic acid , ring (chemistry) , pyrazoline , medicinal chemistry , organic chemistry
Condensations of 5‐(2‐hydroxyphenyl)pyrazoline 3a with 4‐carboxybenzaldehyde, glyoxylic acid and N,N ‐carbonyldiimidazole leading to pyrazolobenzoxazine derivatives were studied. The observed diastere‐oselectivity is discussed. Reaction of 3a with Lawesson reagent gave rise to a new 5 H ‐pyrazolo[1,5‐c]‐[1,3,2]benzoxazaphosphorine heterocyclic system.