title: Hydrazine-mediated cyclization of Ugi products to synthesize novel 3-hydroxypyrazoles.
abstract: 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 potential to be of interest in future library enrichment strategies.
authors.affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, BIO5 Oro Valley, The University of Arizona, 1580 E. Hanley Blvd., Oro Valley, AZ 85737, USA.
authors.forename: Arthur Y
authors.initials: AY
authors.lastname: Shaw
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: McLaren
authors.forename: Gary S
authors.initials: GS
authors.lastname: Nichol
authors.forename: Christopher
authors.initials: C
authors.lastname: Hulme