A practical, metal-free synthesis of 1H-indazoles.
The synthesis of 1H-indazoles is achieved from o-aminobenzoximes by the selective activation of the oxime in the presence of the amino group. The reaction occurs with a variety of substituted o-aminobenzoximes using a slight excess of methanesulfonyl chloride and triethylamine at 0-23 degrees C and is amenable to scale-up. The synthesis of 1H-indazoles under these conditions is extremely mild compared with previous synthetic approaches and affords the desired compounds in good to excellent yields.
Counceller
Carla M
CM
Evans Chemical Laboratories, Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA.
Eichman
Chad C
CC
Wray
Brenda C
BC
Stambuli
James P
JP
D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D007191:Indazoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010091:Oximes / Q000737:chemistry*
D007191:Indazoles; D010091:Oximes