Hydrazine-mediated cyclization of Ugi products to synthesize novel 3-hydroxypyrazoles
摘要:
This report discloses a novel concise synthesis of a series of 3-hydroxypyrazoles 5 via a tandem Ugi/debenzylation /hydrazine-mediated cyclization sequence. Herein, n-butyl isocyanide 4b was utilized as an alternative to classical convertible isocyanides enabling high yielding hydrazine-mediated cyclization. Taken together, a novel class of 3-hydroxypyrazoles 5a-5i was synthesized with a potential to be of interest in future library enrichment strategies. (C) 2012 Elsevier Ltd. All rights reserved.
Hydrazine-mediated cyclization of Ugi products to synthesize novel 3-hydroxypyrazoles
摘要:
This report discloses a novel concise synthesis of a series of 3-hydroxypyrazoles 5 via a tandem Ugi/debenzylation /hydrazine-mediated cyclization sequence. Herein, n-butyl isocyanide 4b was utilized as an alternative to classical convertible isocyanides enabling high yielding hydrazine-mediated cyclization. Taken together, a novel class of 3-hydroxypyrazoles 5a-5i was synthesized with a potential to be of interest in future library enrichment strategies. (C) 2012 Elsevier Ltd. All rights reserved.