New Practical Synthesis of Indazoles via Condensation of o-Fluorobenzaldehydes and Their O-Methyloximes with Hydrazine
摘要:
The reaction of o-fluorobenzaldehydes and their O-methyloximes with hydrazine has been developed as a new practical synthesis of indazoles. Utilization of the methyloxime derivatives of benzaldehydes (in the form of the major E-isomers) in this condensation effectively eliminated a competitive Wolf-Kishner reduction to fluorotoluenes, which was observed in the direct preparations of indazoles from aldehydes. Reaction of Z-isomers of methyloximes with hydrazine resulted in the formation of 3-aminoindazoles via a benzonitrile intermediate.
The palladium-catalyzed direct arylation of 2 H-indazoles with arylbromides for the preparation of 3-aryl-2 H-indazoles was found to proceed in high yields when using only 0.5–0.1 mol % Pd(OAc)2 catalyst and KOAc as inexpensive base. A wide variety of electron-deficient and electron-rich arylbromides and also heteroaryl bromides has been successfully employed. Both electron-withdrawing and electron-donating
A compound having GPR52 agonist activity or a salt thereof is provided.
The compound can be provided as a preventive/therapeutic agent for schizophrenia or the like. The compound is represented by the following formula:
wherein
A represents —CONR
a
— or —NR
a
CO—,
R
a
represents a hydrogen atom or the like,
B represents a hydrogen atom or the like,
a ring Cy1 represents a six-membered aromatic ring which may have one or more substituents in addition to a group represented by -A-B,
a ring Cy2 represents a six-membered ring which may be substituted with a halogen atom or the like,
a ring Cy3 represents a five- or six-membered ring which may have one or more substituents;
X represents C
1-2
alkylene or the like,
m represents an integer of 0 to 2, and
a ring Cy4 represents a six-membered aromatic ring which may have one or more substituents.