Structure determination of N-methyl-1,4,6,7-tetrahydro-5H-indazol-5-ones

ORGN 386

Kurt A. Josef, D. Reddy, Ming Tao, and Robert L. Hudkins. Medicinal Chemistry Department, Cephalon, Inc, 145 Brandywine Parkway, West Chester, PA 19380
The synthesis of N-methyl 1,4,6,7-tetrahydro-5H-indazol-5-ones is examined to determine the regioselective ratio of the N-1 versus N-2 isomers. The previously described cyclization and subsequent de-protection of the 7-(hydroxymethylene)-1,4-dioxaspiro[4,5}decan-8-one, 3, is reported to predominately yield the N-1 isomer, compound 1. Our structure assignment, based on NMR data including NOE difference experiments, is consistent with compound 2 as the major isomer. The experimental conditions used to optimize the synthesis of either isomer are discussed.

 

Physical Organic, Materials, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Tuesday, September 9, 2003 Hilton New York -- Americas Hall 1, Poster

Division of Organic Chemistry
The 226th ACS National Meeting, New York, NY, September 7-11, 2003